Don't be afraid too much, the randomizing of the notes for lower skills is quite obvious, so many people who are not able to spend weeks into "power-leveling musical instrument" will certainly play a cacophony.
I finally made progress. But only with a score of a surprising length. Another unrealistic part of PlaneShift: Absolute beginners in music would start with small scores (especially scales) and practice those to "perfection" before trying more complex melodies.
That would be my suggestion for the development of the music training: Define a range of acceptable note and bar counts per level (decade) to gain practice, and give progress per percentage of randomly matching notes, lowering the randomizing factor at the same time. Beginners only have to practice few notes in a score, but their chance to hit at least a specific percentage of them correctly will rise; on the other hand, too long scores will be too hard to practice – yet. The higher the skill, the longer scores are necessary as well as possible to gain practice, and bad luck in the note randomizer makes a mistake still possible.
This may even practice the notation skills of the player...
But I see that chosing these parameters can be complicated, and we already lack in Rules developers...