Since today's PCs run much faster than the 1980's models, using MIDI as the method forintegrating music into computer software makes sense from the standpoint of CPU economy. In the world of consumer level PCs, MIDI is most commonly used in a couple of ways. First, as already mentioned, as a medium of music playback for games. Second, in use of musicbased programs, utilizing the PCs sound card. MIDI data consists of several different types.
Controllers are messages that change the function or status of the receiving unit.
For instance, Controller 7 sets the overall output volume of the receiving device. Luckily, today's modern instruments use digital circuits to store each sound in ROM or disc. There are specifics in the design of MIDI which set limits on the maximum number of parameters that can exist. For instance, there are a maximum of 128 controllers and patch numbers. The original MIDI design did not assign all the MIDI controller number to a musical function, and never specified what sound should exist at each patch number.