Live music in Brussels?

I've been living here a little while now and ashamedly haven't been to any gigs yet.
 
I love live music and I miss just going to some wee venue and checking out whoever was playing.
 
Do any of you have any recommendations for me? I'm gonna be bored and lonely tonight so instead of moping around and staying in I figured I'd try and find somewhere just go to and enjoy.
 
Thanks!