I've used Winamp since year dot but have recently started to wonder if there are more modern ways to manage and listen to music.

Ideally it would work both on OS X and Windows, on premises but a cloud sync wouldn't harm.

Any thoughts, pointers, war stories?

Ps. Those ancient mp3s that one ripped self or is storing as a security copy for that nice company in Russia, do the big online boys (Google, Apple et al) kick up a fuss should said files be uploaded?