Re: [Rhythmbox-devel] Musicbrainz and RB

[David Scotson <davidscotson mac com>]

On Mon, 2003-08-11 at 15:59, in7y118@public.uni-hamburg.de wrote:
> So lemme get this straight.
...
> 4) Each title has one or more TRM IDs, which get extracted from differently 
> compressed audio streams of a title.
...
> 6) The computation of TRM IDs is not much better than using an md5 of the raw 
> audio data.

Just to be clear the trm is based on the acoustic properties of the
track.

The track *may* have more than one trm attached to it but generally
tracks, each imperfectly ripped in its own way and compressed at a
variety of quality levels with a range of different codecs, will all
converge on a very small number of trm ids (i.e. close to one)

This is orders of magnitude better than an md5 of the raw audio since
every imperceptible ripping flaw, every implementation of every codec,
and every different quality level will produce a different set of data
even if they sound near identical to human ears.


> 2) Titles are different if they are on different albums. (So the same
> song may be different titles if it appears on a studio album as well
> as a Greatest Hits album or a sampler)

As far as I know there is no way (even in theory) to distinguish which
of several originally bit-for-bit identical tracks is the source of an
mp3 without recourse to external metadata, which is what MusicBrainz
currently does.

But this also leads nicely into one of the more interesting uses of
MusicBrainz data. Rather than seeing it as just an improved freedb.org
for naming tracks it allows albums to become virtual playlists of tracks
rather than sticking with the one-album-per-track mapping that is merely
a useless and limiting vestige of their physical origins.

So if I own a track that is on a single, a studio album and two greatest
hits, why do I have to decide which it belongs to? Why can't it belong
to all of them? This allows me to delete duplicates from my collection
to save space and gives me the benefits of owning albums that I never
bought because I already own all (or most of) the songs. So don't buy
the B-Sides collection if you're such a fan that you already bought the
singles, just download the tracklist from MusicBrainz and you're all
set.

This gets even better when you consider Various Artist compilations. I
prefer to buy rereleases and boxsets of an individual artist's or
group's work but sometimes I want to hear "Psychedelic Sounds of the
60's" or "Disco Hits of the 70's" or "The Phil Spector Wall of Sound" or
"Acoustic Moods" or any other thematic mix without laboriously
constructing a playlist myself from individual artists' albums. If
you've ever swapped playlists or CDRs with friends you'll know that it's
always more interesting listening to someone else's tracklist choices.
You may even be inspired to go out and buy the tracks you don't have if
you're particularly impressed with the rest of the compilation.

Of course even if you own one set of VA compilations you may prefer to
listen to the tracks arranged in another way, or if you own Motown
Chartbusters Volumes 1 through 12 you may want to burn "The Greatest
Hits of Diana Ross & The Supremes" onto CD for your mother. The
potential usefulness is astounding.

So there's far more to MusicBrainz than just getting the id3 tags on
your mp3s consistent, though that's a good first step when you've got a
browsing system like Rhythmbox, iTunes or the iPod that repays some
level of data normalisation. But deeper, and more advanced use of the
MusicBrainz data is certainly something to think about for the future.

cheers,

dave