The bedplate is the relatively heavy metal foundation on which all the other pieces are fastened, usually by screws.

The ratchet lever or the windup key is used to put the spring motor under tension, that is to wind it up.

The spring motor or motors (two or more can be used to make playing times longer) give anywhere from a few minutes to an hour or more of playing time.

The comb is a flat piece of metal with dozens or even hundreds of tuned teeth of different lengths.

The cylinder is the programming object, a metallic version of a punched card which, instead of having holes to express a program, is studded with tiny pins at the correct spacing to produce music by displacing the teeth of the comb at the correct time. The tines of the comb 'ring', or sound, as they slip off the pins. The disc in a disc music box plays this function, with pins perpendicular to the plane surface.

Multiple-tune cylinders have more than one set of pins intertwined on the same cylinder, with, for example, the B pins for a second song lying halfway between the B and C pins of the first song, etc. Offsetting the cylinder slightly relative to the comb brings the different set of pins into contact with the tines, thereby playing an alternate piece of music. Many modern music boxes will have as many as four sets of pins intertwined, with a mechanism automatically shifting the cylinder from one song or movement to the next.