Hello, where did you find the 'Complete music sheet'?
Viewing post in Caliross, The Shapeshifter's Legacy comments
For the complete music sheet, you can find one half in a basement near the Queen of Hearts (you must use detect magic behind the building next to the QoH, to find an illusion, and you might need "Dispel" to erase the illusion).
The second half can be found in the slums. There is a temple there, and near the altar there are two hidden switches on the floor (you should be able to stand on one, and use "Push" to activate the other).