It may be helpful to see a music legend, or at least to be able to display a music legend or reference a music legend, from within the app for drummers who are new to reading music and may be unsure which note head and staff position maps to which instrument.
This may also be a useful feature to include on exported PDFs. Maybe the user can choose whether to include a music legend or not, and if so, which kind? A smaller, more abbreviated one, or a larger, more descriptive one?
Please see the attached image which shows an example of two different styles of music legend.