Did no one on the team run any tests before the fixes / improvements to the instruments were deployed? Adding new instruments is great, yet until the instruments truly get fixed (and tested), it defeated the purpose of releasing new instruments in this Patch.
The June 25, 2019 Patch Notes say:
"Increased the limit on the number of musical notes that can be played per second on all musical instruments before their skills are forced to cooldown."
However, that only fixed 'half' the issue with the instruments. The other half of the issue is how fast players are able to play different notes at the same time across different octaves (when the Change Octave buttons are pushed/activated manually by a script or a by using Midi Keyboard, like I use, which makes playing different notes at once across different octaves easier without having to push/activate the Change Octave buttons manually while doing so.
This patch did nothing to fix the real underlying issue with the instruments. Scripts and manually played music worked just fine for the longest time, and those who used scripts or used a Midi Keyboard did not have any issues until after Nov. of 2018.