A nice useful application for editing tags in your audio collection is Kid3, which currently is at version 1.0 and it offers support for all the major formats like OGG Vorbis, FLAC, MP3 or MP4. The good thing about Kid3 is that it allows you to edit tags for several files at once, instead of editing one file, saving and then starting over with the next file.
For listening to music, managing collection and many, many more, Amarok is the right choice. In my opinion Amarok is the most feature-complete and stable audio player not only for KDE, but for Linux in general. And there are strong reasons for being so: Amarok gained its huge popularity because it is complete by any means. The latest stable version is 126.96.36.199 for KDE 3.x, but development is in progress at Amarok 2, which is a complete rewrite (currently in alpha stage) for KDE4, with a new concept, a new interface, and integration of widgets to mention just a few. By the way, if you find editing tags easier to do with your audio player of choice, than Amarok can prove as good as Kid3, since it practically offers the features Kid3 has regarding tag editing.
Other notable players for KDE would be JuK and Noatun, both included in the KDE 3.x packages by default.
For listening to audio CDs any video or audio players. Amarok and Kaffeine both play audio CDs. And there is also KsCD, with the only purpose of playing audio CDs and fetch CDDB data. KsCD is included in the kdemultimedia package in KDE.
For ripping audio CDs, KAudioCreator proves very useful. It allows to rip to OGG Vorbis, FLAC, WAV and MP3, with the possibility to pass command line arguments for specific options that you may need. It's also light in resources, but does a great job ripping your audio CDs.
Although I like to use command line tools like flac and oggenc for ripping and converting audio files, another nice application for converting between various audio formats is soundKonverter, which supports OGG Vorbis, MP3, MP4, FLAC and several more.
Updated: Jul 05, 2008 (Created: Jul 05, 2008)