how can i play midi and wma in linux?
 

i cannot play midi in linux,how can i play it?
and which player can play wma except for mplayer?

Here's a page with lots of midi software - http://www.linux-sound.org/midi.html
Can't help with the second Q.

(eg.)Timidity transforms midi to wav stream in real time.
That's why it will work even if your sound card driver/configuration does't support midi.

You could try avi-xmms XMMS plugin (http://www.xmms.org/plugins_input.html).
It's video plugin, but it works with wma sound in avi/asf. Maybe it would help. !!! I haven't try that !!!