ova is a convenient console frontend for ripping CDs and encoding MP3 and wave files to the Ogg Vorbis format. It is also able to query the CDDB given a CD (or saved CD discid) or several MP3/Ogg Vorbis/wave files (very useful for downloaded albums). Ogg Vorbis files can be tagged and renamed according to elaborate patterns.
ZoltanPlayer is a music playing daemon. It accepts remote commands via its own mini HTTP server and can seamlessly use Audio or Data CDs. Audio CDs are played internally (optionally querying CDDB info servers) and digital songs in audio CDs are played via external players. It's not limited to CDs, as a hard disk directory can also be used.
GrypPhon focuses on adding new features to the old concept of a CD player, while maintaining extreme configurability. It is written purely in Python and contains a Linux CD-ROM audio library for Python containing all normal CD-playing features, plus volume control and skipping/searching.
CDDE is a program that detects when a CDROM drive has a disc inserted. When it finds a disc inserted in the drive it will attempt to determine the type of disc, and execute a specified command. This means a DVD can be inserted and your favorite DVD software will start, or a data CD can be automatically mounted.
mp3cleanup is used to tidy up various aspects of MP3 files, including filenames, ID3 tags, path, m3u playlists, and bitrate. This is particularly useful for hardware MP3 players that sometimes have arbitrary limitations on the files they work (well) with. It can operate on single files or on all the files contained in a directory.
Synaesthesia is an eyecandy program that represents music graphically in real time as coruscating fields of fog and glowing lines. It is intended as a visual accompaniment to music. Its display combines information about the frequency, location and diffuseness of sound. It can take input from CD, line, piped from another program, or from EsounD. It also functions as a CD player.
PostScript::CDCover generates a Postscript program that prints a CD cover and backlabel, with contents displayed as a tree of directories and files. The module ships with a stand-alone, ready-to-use script, pscdcover, that takes the directory tree of a CD-ROM as input and generates a cover from it. The output can be directly fed to a PostScript printer, but it is designed to be easily editable (should one wish to remove unwanted directory entries, for example).