Hey! Wonderful piece of software for creating music with sound effects.
Besides allowing the writting of 4 scores as any other music editor, this jewel also allowed you to embed "POKE" commands in your music to trigger additional actions (such as lights control through the joystick ports to blink synchronously with the tune!).
Also the feature of editing envelopes to create your own sounds, at the speed of vertical blank interrupts, I could produce outstanding sound effects such as carry-over, illusion of 2 sounds with 1 audio channel, etc., I even could write music that sounded as complex as in the game Alternate Reality.
I learned a lot from this beatiful tool, and after this I could write my own utilities to produce the music for "Line-Up", look for it!