Ok, it seems that you didn't configure the Soundblaster in the install.exe of Master of Magic correctly.
At first, don't the select the Soundblaster music, it sounds pretty lame and choppy in DosBox. Choose General Midi instead. Select Configure card then. Let the values at their default positions (adress 330, DRQ 2). It takes little longer to load the game then, but that's worth it - the music is very good then.
Then choose Soundblaster Pro (Later) and set the values as this: adress 220, IRQ 7, DRQ 1.
Enjoy the music and sound and have fun with the great game!
