Evil player is focused on speed. Its interface isn’t beautiful at all, but if what you want is to listen your music with a program which doesn’t consumes resources, it is what you are looking for.
Evil player only includes basic features, though you can download plug-ins to enhance it.
There are better players, but it’s probably the fastest and simplest one.
It supports WAV, OGG, MP1, MP2, MP3, MOD, XM, IT, S3M, MTM, and more formats.