Let me give a few examples of instances where the instrumentation pertaining to a composition is wrong
This composition is for violin and piano, and although the original composition that this arrangement is based on is written for solo piano, this second piano in the composition title should not be interpreted as participating in the instrumentation.
Another example (that’s very frequent!):
There’s hundreds of compositions from the (pre-)classical era when keyboard compositions could be played on both harpsichord and fortepiano, but not on those two instruments at the same time. It was a period of transition, so these composition titles are correct, but the instrumentation should be named “keyboard solo” or “solo keyboard”.
I have played around with altering the composition title a bit and found out that Roon apparently “calculates” the Instrumentation metadata by adding up any and all intruments named in that title. Now in simple cases such as “Sonata for violin and piano” the algorithm works, but as soon as parentheses come into play, things go seriously wrong, thereby making the whole Instrumentation tag totally unreliable.
If Roon sticks to calculating the Instrumentation metadata itself because Instrumentation information is not supplied by TiVo, then the underlying algorithm should be made smarter. To start with, anything between brackets should be ignored.
Found another one just now:
There’s nothing ‘solo’ about two pianists sharing the keyboard, is there?
(Unless of course, some very special artist has grown an extra pair of hands…)