Scores and parts, what to keep together/separate:
chamber music, all pamphlets: keep together
chamber music, score has multiple signatures, parts are pamphlets: separate score and parts
chamber music, score is either miniature or folio (and parts are regular size): separate score and parts
2 performers, published separately, identical scores: make copy 1-2
if published together (ie. 300 2 identical scores...), they circulate together as one item/copy
2 pianos, separate parts, pamphlets: make score and part
2 pianos, separate parts, each multiple signatures: make separate pno 1 and pno 2, to be bound separately
In a case between cost and consistency, cost always wins. (i.e. Score has already been bound and the parts come in, leave the score as is and keep the parts separate) Make sure to include "Score" or "Parts" in the call number for each separately circulating item.
Pamphlets: when you have a few sheets folded in half and stapled down the middle
Multiple signatures: anything else