Music files?
 

Is a .cdr file the same as a .cda file? I have a huge mp3 collection and want to burn some cd's. I know i have to convert them over to another format because my cd player isn't going to reconize an mp3 file. When I play a cd in xmms it tells me that the tracks are a track01.cda file and in sox it says to record an audio as a .cdr file and both are 44khz sample rate.

If you wanna burn audio CD's use K3B - you just drop the MP3 files into an audio project and it converts them to the correct format for you (which is 44,100 Khz, 2 channel, 16 bit WAV file I think).