Sure. Musical calculators were initially made for the blind (so when you press a key, you hear a sound and can tell what's happening.) When you press equals, for example, the calculation happens and the calculator sounds out the tones for the answer - for example, you enter 9x9=81, and you get (9 tone) (multiply tone) (9 tone) (equals tone) and then the calculator sounds out (eight tone) (one tone).
Eventually people started using them as toys or musical instruments, so some calculator companies started making the sounds less robotic and more musical - and now there are "musical calculators".
