Edit the sound of a note within MIDI to make playback more realistic.

I was thinking of a feature where you could go into the settings of any note and change how it sounds in playback to whatever you want, as long as it's within the note duration.

For example, if I want to make a two-note marimba roll, it would be notated as a dyad with a tremolo. However, in playback, this would sound like the two notes being played really fast at the same time, which is not how you would play a marimba roll. In order to make the playback correct, you would have to notate it as a tremolo between the two notes. As well as that, Musescore doesn't allow you to crecendo percussion tremolos (yet?), so you would have to make the two note tremolo into 8th notes and extend over the entire measure (if the roll is a whole note.

In summary, I would like a feature where you can write this:

but make it sound like this:

in playback. What I've been doing is putting both of them on top of each other, setting the ideal playback notation to voice 2 and invisble, and setting the proper notation to not play, however, this can get cluttered very quickly.