I don't mind having library management, and I would love to have a Linux clone of foobar2000. Nothing else has its tag management and search/sort capabilities.

I put lots of custom tags in all of the tracks I've ripped, downloaded, or recorded live, and I have yet to come across a Linux music player that allows me to search them or sort by them.

Clementine comes close, but not quite close enough. Maybe I need to get some Copious Free Time and rip into its sources.