Slash Notation Playback
Current playback of slash notation sounds like it might be from the soundtrack of "Children of the Corn" just a constant single note played over and over and over.
Better behavior would be to playback chords as spelled in corresponding chord symbols (piano and guitar), root note of symbol for bass and simple hit on ride cymbal for drums played back in rhythm of the slashed notation.
Attached is rhythm section example.
Also, for reference: https://musescore.org/en/node/288584