Ableton's Bouncy Notes device can generate a full marimba melody on its own using Auto mode. Setting the scale to minor pentatonic with the tonic on D and the starting note at D2 keeps every bounced note musically locked in, so the randomness never sounds wrong.
Quantizing to 16th notes and pushing the drop rate higher gives the melody a steady stream of notes to work with, while narrowing the range keeps them from wandering too far. Randomizing the direction adds unpredictability to the melodic contour, and raising Gravity makes each note hit with more force, giving the line a physical, evolving feel rather than a static loop.
Once the melody is generating, a simple bassline underneath is enough to turn the auto-generated pattern into a full arrangement. The same Gravity and Lifetime controls can be pushed further on drum material to make hits feel heavier and more extreme, showing how the same few parameters adapt across completely different instrument roles.