Why does MAI produce MIDI?

In order to reach a high level of musical adaptivity the music needs to be composed at runtime, note by note. This is what MAI does. New music is constructed, moment by moment, at runtime from the material in the tunes given as input. You cannot record what is not yet composed. To perform this just recently composed music, you need musical instruments. If you are a piece of software in need for musical instruments, a MIDI interface is the natural choice. In other words, there is no time to record the music, MAI is improvising live!