Thank you Charlie Fogle for your explanation, it is very detailed indeed !

Only here, when I try to modify the MIDI phrase (which is not shown in your video), we can't do that.

In your method, you can change the SOUND (choose a real track instead of MIDI, change the instrument (finger bass instead of picked bass), mute / solo) but you cannot change the CONTENT of the MIDI (choose a different riff), you cannot neither "Select MIDI" SuperTrack for this track ... "or" Select Custom MIDI Style for this track ... "without stopping the playback.