Newander, the Collectors bonus disc has four mp3 on it:
IceWalls Balle - 2.2MB
Kuldaha Valley Theme - 2.1MB
Shaengarne Bridge Battle - 1 MB
Targos Docks Theme - 2.4MB
You could also try PlanetBaldursGate IceWindDaleII
http://www.planetbaldursgate.com/iwd2/media/files/
It has Audio sample of music of three mp3 files which appear to be about the same size as those on the bonus disk
Sample1 - 2.2MB
Sample2 - 2.4MB
Sample3 - 2.3MB