audio-info-examples

Audio Info

The web has been incorporating multimedia into its pages ever since the release of the Mosaic web browser around 1993. It was shortly thereafter that links to many types of audio started to appear on the web. Even today (April 2007), it is still difficult for a web browser to extract semantic information regarding audio recordings from a web page. Information such as artist, title, speaker, track listing, and publisher are readily available on the same web page that contains the links to the audio files. The Audio Info exploratory discussion is an attempt to create a standard method of marking up metadata and information about one or more audio recordings discussed on a web page.

The Problem

It is difficult for a browser to extract semantic information about an audio recording described on a web page. Metadata such as speaker, musician, publisher, label, title of the work, release date, acquisition link, related image artwork and tags provide relevant context for the audio recording.

Having such information marked up can provide a number of benefits to the viewer. If a web browser understands that a particular web page contains a song performed by an artist, it can produce richer interactions. For example, specific searches may be performed for artists and songs via general search services such as Google and Wikipedia. Specific search services may also be queried such as MusicBrainz, The Internet Archive, FreeDB, or Bitmunk. Additionally, classification by crawlers can become more accurate. If there are 20 tracks found on a page done by the same artist, and that content consumes a significant portion of the page, it can be assumed that the page is not only about music, but also about a particular artist.

The audio information need not be associated with a file. Note that audio content (The Payback by James Brown) is very different from the audio file format (192Kbps, stereo MP3). The goal of this discussion is to create a Microformat draft for marking up audio metadata and information.

A NOTE ABOUT CONTRIBUTING - USE TEMPLATES

Due to the large number of audio sites, tallying statistical information for this discussion is difficult. A small python script has been written to do the job, but for it to work, we need to be careful about how we mark up information.

Please use the following template when adding information about an audio collection description:

* [ http://www.example.com Website Name]
** [ http://www.example.com/album_example/ Album Example]
*** Information displayed: artist, title, tracks, release date, label, genre, web-based purchase, cover image, 
                           price, format, sample, length, summary, physical-based purchase, publisher, reviews 

Please use the following template when adding information about an audio song, track or sample description:

* [ http://www.example.com Website Name]
** [ http://www.example.com/song_example/ Song Example]
*** Information displayed: title, track number, sample, web-based purchase, artist, price, length, release date, album, genre, format, rating, label 

If you need to add more information that is displayed, please use a common term to describe the information. For example, if you need to mention that an artists hometown is mentioned, adding a term such as hometown would be acceptable.

Authors

• Manu Sporny, Bitmunk - Digital Bazaar, Inc. (PI, editor)
• Charles Iliya Krempeaux
• Joshua Kinberg
• Rod Begbie
• Chris Messina
• Alexandre Van de Sande

Contributors

• Tantek Çelik
• Dean Hudson
• Andy Mabbett
• Martin McEvoy
• Mary Hodder
• Scott Reynen

Real-World Examples

Speech

Publication of audio speeches on blogs is often called "podcasting". In essence though, it is simply audio speech publishing. Quotes of audio files are beginning to appear, and publishers are putting up files with links to other audio files they've quoted from. Most audio appears to often have the same base elements as video and photos, with the exception of quotes.

Individual Publishing of Speech

• Microformats: Web Essentials Audio
  • Appears to be composed of:
    • title/summary of the recording
    • clickable hyperlink to the recording (MP3)
  • Contextual:
    • (primary) speaker is indicated in nearby text

• Chris Pirillo podcast
  • This example has a Title, Html URL, media URL(s), description or summary, categories/tags underneath what is viewable, and date. +10k

• Reflog's Random Thoughts podcast
  • This example has a Title, Html URL, description or summary, creator, tags and publish time and date. +10k records.

• Evil Genius Chronicles podcast
  • This example has a Title, Html URL, description or summary, quotes URLs and descriptions, licence, creator, tags and publish time and date. +10k records.

• media published from a blog, Jake Steinfeld's Audio Blog NOTE: this record had trouble because mediawiki blocks any DOTbiz domains and so while this domain coincidentally has a DOTbizbyjake.com name that is not a TLD, it was still blocked in the loading of the page with this example. So please adjust the URL manually and then visit the site.
  • This example has a Title, Html URL, media URL, creator and publish time and date. +10k records.

• Matt's today in history
  • mp3 episode example
    • Information displayed: Title, transcripts, download link, rss feed, author

• Buzz Out Loud
  • episode example
    • Information displayed: Title, episode summary, length, date
    • Information displayed on a separated page: Title, episode summary, lenght, date, show links, voice mail, emails received

• Ruby On Rails Podcast
  • Appears to be composed of:
    • title, contributors/artist, album, and length.
    • clickable hyperlink to the recording (MP3) or (MP4/M4A).
  • Contextual:
    • Some transcripts of certain episodes are available.
  • Examples:
    • Single episode Jack Dorsey and Alex Payne of Twitter.
    • All episodes since 2005.

Audio books

• Audio Darwin

Music

Retail

• Naxos music - a mixture of single artist, single composer, multi-artist and multi-composer classical releases. Also jazz and audio books.
  • GRANADOS: Piano Music, Vol. 10 - In the Village - multiple composers
  • ADAMS: Shaker Loops / etc. - ,ultiple composers, single conductor (also a composer)
  • BEETHOVEN: Missa Solemnis, Op. 123 - single composer, conductor, choir, soloists
  • CHOPIN : The Best of - single composer, multiple artists
  • FAMOUS PIANO PIECES - multiple composers, multiple artists
  • many more combinations to follow

Individual Publishing of Music

• Brad Sucks » music
  • Has album title, song title, separate link to more info, inline flash player, and play link (to mp3)

• Scott Andrew - lo-fi acoustic pop superhero! > music >
  • Has album title, song title, album artwork, streaming link (to m3u), and play link (to mp3)

• Portishead Remixed
  • Whole page is for one album (a mash-up remix of a Portishead album). Has Album Track Number and Title (linked to mp3) and Remixer's name, plus cover art. Also a link to the BitTorrent download of the whole album.

Music Podcasting

Music podcasts are a totally different beast, but a very important one. They usually consist of one big file containg multiples songs, speech, audio advertising and prerecorded audio (such as voicemail or promos). Podcasts consists of multiple songs and therefore might need another microformat, one that makes a collection of multiple songs and only one file.

Properties

These properties are in alphabetical order and in no way represent the frequency of their use in the examples. The property names are also not final and probably will not be used when the Microformat vocabulary is decided. Deciding the vocabulary of the Microformat is not performed at this stage of examples collection and analysis. These property names and definitions are listed here in an attempt to keep the current and future example analysis teams using the same definitions for property names.

• RSS Feed - An RSS feed for the podcast exists on the page.
• contributor - The person that created or helped create the podcast.
• description - The description of the podcast.
• download - The full download location for the podcast.
• format - The audio format for the podcast.
• genre - The genre for the podcast.
• label - The publishing company for the podcast.
• length - The length of the podcast.
• photo - A representative image of the podcast.
• position - the number or index of the podcast.
• price - The price one must pay to legally acquire the podcast.
• published - The date the podcast was released.
• sample - A sample of the podcast
• section - The name of a section of a podcast.
• title - The title of the podcast
• web-based purchase - A place to legally pay for and acquire the full podcast.

Examples

• Coverville
  • Properties: RSS Feed, description, title, published, contributor, position, download

• Magnatune Podcasts
  • Properties: title, section, genre, length, published, contributor, position, download

• Radio Clash
  • Properties: RSS Feed, description, title, photo, section, format, length, published, contributor, position, download

• Daily Source Code
  • Properties: RSS Feed, description, title, photo, section, genre, published, contributor, position, download

• Rock and Roll Geek Show
  • Properties: RSS Feed, description, title, section, format, genre, length, published, contributor, position, download

• Accidenth Hash
  • Properties: RSS Feed, description, title, photo, section, genre, length, published, contributor, position, download

• Veer Cast
  • Properties: RSS Feed, description, title, length, published, position, download

• Three Hive
  • Properties: RSS Feed, description, title, photo, section, format, genre, published, contributor, position, download

Mashups, remixes, cut-ups and audio-collages

Some music is in fact made from other samples of other music. The information on those tracks then must contain another audio information, on the original track. Some of those tracks are posted to sampling communities and therefore are remixed again, creating a fractal-like information. Most sites, thou, will only show the first layer: the music directly derivated

• [ http://www.example.com Website Name]
  • [ http://www.example.com/song_example/ Song Example]
    • Information displayed: title, track number, sample, web-based purchase, artist, price, length

• Mashup of the week
• banned music
• illegal art
• cc mixter a creative commons community

Top Lists

Top lists are lists of music or audio that are rated in order. Examples are a the "Billboard Top 100", "Top 100 Blue Grass hits of 2005", "Top Beatles Remixes of All Time", etc.

• About.com: Top 10 Hot Pop Songs July 10, 2007
  • contains: position, hAudio
• Channel 4 100 greatest Albums THE 100 GREATEST ALBUMS
  • contains: Position, Artist, Album
• BBC Radio 1 Singles Chart Radio 1 Singles chart
  • contains: Title, Artist, Photo, artist url, record label
• BBC Radio 1 Download Chart Radio 1 Download Chart
  • contains: Position, Artist, Title, Record Label
• Amazon UK top 2007 singles so far 2007's Best Singles...So Far!
  • contains: Position, Title, Artist, Review, Image, Purchase url
• Freaky Trigger top 100 songs of all time Top 100 Songs of All Time
  • contains: Position, Artist, Title
• List of songs in English labeled the best ever (Wikipedia) List of songs in English labeled the best ever
  • contains: Sorting By Alphabet, Artist, Track, cites from press
• The Billboard Hot 100 The Billboard Hot 100
  • contains: Position, Artist, Title, Imprint, Catalog No, Distributing Label
• New Musical Express Tracks Of The Year 2006 NME Tracks Of The Year 2006
  • contains: Position, Artist, Title, Image.
• Here Ya Music Blog Top 100 indie singles of all time Top 100 Indie Songs of All Time
  • contains: Position, Track, Artist, Album, Record Label, Year
• The Rolling Stone 500 Greatest Albums of All Time The RS 500 Greatest Albums of All Time
  • contains: Position, Album Title, Artist
• The Official Chart Company (UK) top 100 singles Top 100 Singles Chart
  • contains: Position, Previous Position, Artist, Title
• Every Hits Top 100 All-Time 'Worst Ever' Singles 100 All-Time 'Worst Ever'
  • contains: Position, Artist, Title

Service Publishing of Music

• AudioFind
  • Properties: album artist, track title, album title, album label, album release date, track number, track sample, track web-based purchase, album genre, album web-based purchase, album cover image, track length, track price, album price, description, track rating, album album rating, album style, album artist rating

• Telstra BigPond
  • Properties: album artist, track title, album title, album label, album release date, track number, track sample, track web-based purchase, album genre, album web-based purchase, album cover image, track artist, track price, description, track album, album non-subscriber price, album subscriber price, track add to pop-list

• Bitmunk
  • Properties: album artist, album tracks, album label, album release date, track number, track web-based purchase, album genre, album web-based purchase, album cover image, track artist, description, track release date, album sample, track album, track label, track composer, album payees, track total price, album p2p-based purchase, track genres, track payees, album album title, track song title, track p2p-based purchase, album total price

• Download Punk
  • Properties: album artist, track title, album title, album label, track sample, track web-based purchase, album web-based purchase, album cover image, track price, album physical-based purchase

• FYE
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track number, album genre, album cover image, track artist, description, album format, album physical-based purchase, album reviews, album styles, album product id, album regular price, album store price, album UPC, album production credits, album savings

• iMusic
  • Properties: album artist, album title, album tracks, album label, album release date, track number, track sample, track web-based purchase, album genre, album web-based purchase, album cover image, track length, track price, track release date, album length, album number of tracks

• AON Music
  • Properties: album artist, track title, album tracks, album label, track number, track sample, track web-based purchase, album genre, album web-based purchase, album cover image, track length, track price, album price, album format, album sample, track format, album bitrate, album number of tracks, track add bookmark, album album, album add bookmark

• TDC Online
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track number, track sample, track web-based purchase, album web-based purchase, album cover image, track price, album price, album format, album length

• Audio Lunchbox
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track number, track web-based purchase, album genre, album web-based purchase, album cover image, track length, track price, album price, album format, album bitrate, album add to wishlist, album sample (flash applet), track sample (flash applet), track price in credits, album price in credits

• Chaos Music
  • Properties: album artist, track title, album title, album tracks, album release date, track number, album genre, album cover image, album price, description, album format, album physical-based purchase, album add to wishlist, album availability

• Sony Connect
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track sample, track web-based purchase, album genre, album web-based purchase, album cover image, track artist, track length, track price, album price, album length

• Digirama
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track number, track sample, track web-based purchase, album genre, album web-based purchase, album cover image, track length, track price, album price, album reviews, album license, album related albums, album also bought

• eMusic
  • Properties: album artist, album title, album tracks, album label, track number, track sample, track web-based purchase, album genre, album web-based purchase, track length, album sample, album length, album reviews, album album rating, album styles, album save to playlist

• FNAC
  • Properties: album artist, track title, album title, album tracks, track number, track sample, track web-based purchase, album genre, album web-based purchase, album cover image, track length, track price, album price, description, album length, album add to playlist, track add to playlist

• Sanity
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track number, album cover image, album price, description, album physical-based purchase, album price in points, album SKU, album catalog ID

• MisRolas
  • Properties: album artist, track title, album title, album tracks, album release date, track number, track sample, track web-based purchase, album web-based purchase, album cover image, track artist, track price, album price, album reviews, album number of tracks, album album rating, track add to wishlist

• MTV
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track number, track sample, album cover image, album physical-based purchase, track video sample

• Musica360
  • Properties: album artist, track title, album title, album tracks, track web-based purchase, album web-based purchase, album cover image, track artist, track price, album price, album samples (flash)

• Musicload
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track number, track sample, track web-based purchase, album genre, album web-based purchase, album cover image, track artist, track length, track price, album price, album format, track release date, album sample, album length, track album, track label, track genre, track format, track rating, album bitrate, album rating, track comments, album quality, track quality, album comments

• Napster
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track number, track sample, track web-based purchase, album web-based purchase, album cover image, track artist, track length, album price, description, track release date, album sample, track album, track label, album reviews, album number of tracks, album track count, track album title, album review, album share

• PartyMob
  • Properties: album artist, track title, album title, album tracks, album release date, track sample, track web-based purchase, album genre, album web-based purchase, album cover image, track artist, track length, track price, album price, album format, track release date, album sample, track genre, track format, album bitrate, album number of tracks, album track count, album total length, album quality, track quality, track DRM information

• Peer Impact
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track number, track sample, album genre, track artist, track length, track price, album price, album format, album track count, album purchase (application link)

• Pure Tracks
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track number, track sample, track web-based purchase, album web-based purchase, track artist, track length, track price, album price, description, album length, album total length, album disc count, track label (popup), album DRM information

• Reggae Country
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track sample, track web-based purchase, track artist, track length, track price, album price, album web-based purchse

• Real/Rhapsody
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track number, track sample, album sample

• Ruckus
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track number, track sample, track web-based purchase, album genre, album web-based purchase, album cover image, track artist, track length, track album title

• Sanity
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track number, track sample, album web-based purchase, album cover image, album price, album catalog id

• [Album Starzik SARL]
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track web-based purchase, album genre, album web-based purchase, track artist, track length, album format, track release date, album length, track label, track genre, track format, album bitrate, track composer, track album title, track size, track bitrate, album size, track creators, track performance artist

• [1] CellCity]
  • Properties: album artist, track title, album tracks, album label, album release date, track web-based purchase, album genre, track price

• top100.cn
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track number, track sample, track web-based purchase, album genre, album web-based purchase, track artist, track price, description, album sample, track label, track genre, track comments

• Wippit
  • Properties: album artist, track title, album title, album tracks, album release date, track number, album genre, album web-based purchase, track artist, track price, album price, album format, track release date, track album, track genre, track format, track size, track file type, track web-based purchase link

• Yanga
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track number, track sample, track web-based purchase, album genre, album web-based purchase, album cover image, track length, track price, album price, description, album sample, track rating, album rating

• [Album somesongs]
  • Properties: track title, track sample, track artist, track release date, track rating, track summary, track reviews

• Magnatune
  • Properties: album artist, track title, album title, album tracks, album release date, track number, track sample, album web-based purchase, album cover image, track length, description, album length, album physical-based purchase, album license, album artist location, album total time

• SONG FIGHT!
  • Properties: album artist, track title, album title, track sample, album cover image, description, track release date, album artist location

• Yes.com
  • Properties: album artist, track web-based purchase, album cover image, track artist, track cover image, track rank, track played-by radio station

• MySpace
  • Properties: album artist, track title, album title, album tracks, track sample, album cover image, track artist, description, album sample, album number of plays, track lyrics, track number of plays

• MusicBrainz.org
  • Properties: album artist, track title, album title, album tracks, track number, album cover image, track artist, track length, track album, track id, track relationship, track artist id, track album id, album disc id

• Vorbis Comment Recommendations
  • Properties: album artist, track title, album title, album label, album release date, track number, album genre, album cover image, track artist, track length, description, track release date, track album, track label, track genre, album license, track composer, track album title, track summary, track copyright, album part number, track cover image, track arranger, album comment, track location, album copyright, track disc number, album arranger, album isrc, album ensemble, track file type, album encoding, album ean/upn, track lyrics, track isrc, track conductor, track genres, track ensemble, album conductor, track part, track lyricist, track part number, album performer, album part, album version, track version, track comment, track opus, album author, track source media, album composer, track encoding, track encoded-by, track author, track performer, track label number, album location, track tags, album disc number, track ean/upn, track license, album encoded-by, album lyricist, track creators, album source media, album label catalog number, album opus

• iTunes RSS extensions
  • Properties: track title, album title, track sample, album genre, album cover image, track artist, track length, description, track release date, track format, track id, track summary, album owner, album owner e-mail, album website, album language, track tags, album licensing

• Discogs
  • Properties: album artist, track title, album title, album tracks, album label, album release date, track number, album genre, track artist, album format, album rating, album catalog id, album style, album notes, album country

In-active Music Services

• Yahoo! Music Unlimited
• Musicmatch (Merged with Yahoo! Jukebox)
• MusicNet (Service Provider)
• AOL Music Now (Merged with Napster)
• Nate.com (Appears to be Korean, cannot find album examples)
• Next Radio (Service Provider)
• Soundbuzz (Requires MS IE6)
• Starbucks (Requires Flash 8 player)
• Street CDs (parked domain name)
• Synacor (Service provider)
• Telecom Italia (Service provider)
• Pixbox (Terra) (Windows application)
• Virgin Digital (merged with Napster)
• Virgin (Requires Windows)
• Yeahronimo (Commodoreworld)

Discographies

Pages about audio recordings, but not necessarily downloadable files or purchasable product:

• Soundtrack Collector
  • The Legend of 1900
• Wikipedia
  • The Dark Side of the Moon

Analysis

Analysis of Music Podcasts

Podcast Statistics (8 sites analyzed)

• title: 100.00%
• published: 100.00%
• position: 100.00%
• download: 100.00%
• RSS Feed: 87.50%
• description: 87.50%
• contributor: 87.50%
• section: 75.00%
• length: 62.50%
• genre: 62.50%
• photo: 50.00%
• format: 37.50%

Analysis of Music Services

Shown below is the most popular information listed for music albums and songs. This includes analysis of over 84 online music sites.

Album and Song Statistics (41 current sites analyzed, 84 total sites analyzed)

• album artist: 95.12%
• track title: 90.24%
• album title: 87.80%
• album tracks: 80.49%
• album release date: 73.17%
• album cover image: 73.17%
• track number: 70.73%
• album label: 68.29%
• track sample: 68.29%
• track web-based purchase: 60.98%
• album web-based purchase: 60.98%
• album genre: 58.54%
• track artist: 56.10%
• track length: 51.22%
• track price: 51.22%
• album price: 48.78%
• description: 39.02%
• album format: 26.83%
• track release date: 26.83%
• album sample: 24.39%
• album length: 21.95%

Microformalyze Data Files

You will need to use Microformalyze to read and analyze these data files:

• Music Services Microformalyze data file
• Music Podcasts Microformalyze data file

Further Analysis Regarding Summaries

Martin McEvoy did a more concentrated analysis on album/podcast/track summaries and found that the initial analysis was too constrained when it came to identifying if an album/podcast had a summary or not. His findings are available below:

• Podcasts 100% of 8 available sources
• Individual Publishing of Music 100% 0f 2 available sources
• Music Podcasting 80% of 9 available sources
• Mashups, remixes, cut-ups and audio-collages 50% of 4 available sources
• Service Publishing of Music 54% of 39 available sources.

Podcasts

Podcasts: 100% or available sources

• Web Essentials Audio: yes
• Chris Pirillo podcast: yes
• Reflog's Random Thoughts: yes
• Evil Genius Chronicles podcast: yes
• Jake Steinfeld's Audio Blog: yes
• Matt's today in history: yes
• Buzz Out Loud: yes
• Ruby On Rails Podcast: yes

Individual Publishing of Music

Individual Publishing of Music: 100% of available sources

• Brad Sucks music: yes
• Scott Andrew - lo-fi acoustic pop superhero!: yes
• Portishead Remixed: unavailable

Music Podcasting

Music Podcasting: 80% of available sources

• Coverville:yes
• Magnatune podcasts: no
• Radio Clash: yes
• Daily Source Code: yes
• Rock and Roll Geek show: yes
• Accident hash: yes
• Veer cast: yes
• Concert Blast: yes
• 3 hive podcast: some

Mashups, remixes, cut-ups and audio-collages

Mashups: 50% of available sources

• Mashup of the week: yes
• banned music: yes
• illegal art: no
• cc mixter: no

Service Publishing of Music

Service Publishing of Music: 54% of available sources

• AudioFind: yes
• Telstra BigPond: yes
• Bitmunk: yes
• Download Punk: no
• FYE: yes
• iMusic: no
• AON Music: no
• MSN music: yes
• TDC Online: yes
• Audio Lunchbox: no
• Chaos Music: no
• Sony Connect: unavailable
• Digirama: no
• eMusic: unknown login required
• FNAC: yes
• Sanity: yes
• MisRolas:no
• MTV Shop: yes
• Musica360: no
• Musicload: no
• Napster: yes
• PartyMob: no
• Peer Impact: yes
• Pure Tracks: no
• Reggae Country: no
• Real/Rhapsody: no
• Ruckus: unknown, login required
• Sanity: no
• Starzik SARL: no
• CellCity: unavailable
• top100.cn: yes, I think (chinese)
• Wippit: no
• Yanga: no
• somesongs: no
• Magnatune album: yes
• SONG FIGHT!: yes
• Yes.com: no
• MySpace: yes?
• MusicBrainz.org: no
• Vorbis Comment Recommendations: shouldn't be here
• iTunes RSS extensions: hmm? shouldn't be here
• Discogs: no
• Last.fm: no

Existing Practices

Listed below is an overview of existing patterns and practices found in the wild for audio information and metadata.

Other schema

• MPEG4 - includes list of field names, for example "Genre", "Track number", "Disk number".

Summary of common patterns discovered

• There are two major forms of audio - single recordings and collections of recordings. Sometimes an audio collection can exist within a single file, with each recording playing back-to-back within the file. -- ManuSporny
• On music service sites, the audio album is almost always described on the same page as the track listings. -- ManuSporny

Other attempts to solve The Problem

• media-info-examples - Attempted to find an uber-microformat for describing media. Turned out to be too large of a task, thus the problem was split into attempting to create microformats for audio, video and images.
• audio-info-formats - Various formats have attempted to describe audio metadata from within the files.

Related Pages

• hAudio
• hAudio cheatsheet - hAudio properties.
• hAudio authoring - learn how to add hAudio markup to your existing web pages.
• hAudio issues - issues with the specification.
  • Audio info issues - issues with the preparatory work.
• hAudio brainstorming - ideas for the specification.
• hAudio-history - the history of the research and development of hAudio.
• rel-enclosure
• Normative references for tags used