Do the tracks need to be the same bitrate as the original tracks? i.e. 128 kbps?

I tried adding in new tracks with Xiran's Better Music System and got CTDs whenever it tried to play the track. Same thing happened without the mod, when I just put a track in the Explore folder. I don't remember the exact bitrate of the tracks I added, but it definitely wasn't 128. This happened with multiple tracks, too.

And, if this is the case, what tools could I use to create 128 kbps versions of the tracks I want to add?