I'm not talking about add more tracks to the midi recorder of the standalone.   But what about a option to record a midi file while playing and listeninf to a base midi file?

For example:  Someone record a basic melody, and want to add some few more things, maybe a extra melody for the bass or trebble. He plays the midi file and start to play while listening to it, adding more variances.

When he save the midi recording, it would be the combination of the midi he listened and the midi he played.
It could be recorded as a sister track, or a combination of both in a single track.

Also, could be possible to play over the initial midi as the same piano, or as a second piano. This would allow to record different instruments.

It just require a few more options in the track recorder. The appearance would not cahnge, needer the layout space.

And off course, a option to record a mp3 of the hybrid performance.