MP3 is the "hot not-so-new format" for the efficient transfer of music across Internet links. It is vastly more compact a data format than traditional CDs; this comes with some loss of resolution, but mostly from the use of data compression, where music has enough patterns to be considerably compressible.
The potential is quite subversive in a practical sense; artists may popularize their music by publicizing samples in MP3 form, and then, by avoiding the central control of the music stores, sell more directly to fans.
The CD could diminish in price from $15 to $5, and the artist nonetheless watch their revenue from the sale rise from maybe $1 to $2 or $3...
Not surprisingly, the traditional "music industry" seems to consider MP3 to be an enemy of their hegemonic control over the sale of music; the danger to them is not primarily the result of the ability people get to make illegal duplicate copies of recordings, but rather the potential for artists to connect directly to the market, thereby shutting them out.
Ogg Vorbis is a completely open, patent-free, professional audio encoding and streaming technology with all the benefits of Open Source.
Cdparanoia extracts audio from compact discs directly as data, with no analog step between, and writes the data to a file or pipe in WAV, AIFC, AIFC or raw 16 bit linear PCM. The Paranoia IV library (to be released with cdparanoia as alpha 10) is a larger effort to provide uniform generic (packet) and specialized interfaces across platforms.
Linux MP3 Standalone Players Project Page
Various MP3-related Links; not highly useful in documenting why one would care to visit the links, unfortunately.
A highly featureful music player providing similar functionality to winamp , but running on Unix / X11.
CD-Writing HOWTO: Burning CD-Rs (including audio)
Note that getting this to work properly can be a bit challenging for audio material; cdrecord can cope only with a limited scope of frequencies and data formats; I had to take material from the above web pages, and modify the mpg123 parameters, in order to get output that was at appropriate speed/frequency as well as being playable.
Gronk - JWZ's MP3 Jukebox for Unix
A shell script that takes a list of MP3 files and burns them as CDDA tracks onto a CD, playable in most CD players.
Unix -based tools for managing tracks on a Diamond Rio 500 MP3 player.
Project by Real Networks to have an "open source" media player