I was searching through the api looking for something where I can access, display and/or modify the ID3 tags of my .mp3 collection. All I could find that I thought may apply would be the javax.sound.* api. However, nothing in there had anything to do with what I was looking for. Any suggestions?
There is nothing in the Java Sound API (the classes in javax.sound and subpackages) that supports MP3 files, so you won't find anything there. The Java Sound API does have a pluggable architecture, so that people could add support for file formats such as MP3, so it is possible that someone wrote an MP3 support module, you'd have to search Internet for that.
There is an MP3 plugin for JMF (Java Media Framework, the Java multimedia API): Java MP3 PlugIn. Ofcourse you need to have JMF installed to be able to use this (JMF is an add-on package, it is not part of the standard Java installation).