Most signature Williams scores show two 5 line percussion staffs. Tuned and non pitched percussion instruments seem to be distributed over these two staffs without clear rules. Does anyone has more info about the philosophy of this choice of notation?
The two staffs definitely do not represent two players switching instruments. Also no logical player groups like e.g left and right side of the stage seem to fit. In some scores e.g Star Wars Main Title, instruments like Piatti even move from Percussion 2 to Percussion 1 during the piece.
I have copied a lot of Williams scores (in Dorico) from the John Williams signature series edited by H. Leonard to create mockups using virtual instruments and use separate staffs for each percussion instrument and only after finishing the complete piece combine them in a percussion kit as in the original score but it would be interesting to know why these combinations are chosen by J. Williams, his orchestrators, or the people who prepared the published scores.