I got some more:
DAMN YANKEES ("Shoeless Joe", and, of course, the spot where it is mentioned in the "Overture", and kicks off with a furious banjo solo). Other than that, it is all guitar.
THE PAJAMA GAME '06 (banjo on "Once-A-Year Day", and tenor uke on "The Three Of Us")
LITTLE SHOP OF HORRORS '03 (mandolin on "Mushnik and Son")
WICKED (guitar 1 doubles banjo on "Have a little drink" section of "No One Mourns," mandolin on "Something Bad" and "Thank Goodness, and guitar 2 doubles banjo on "Thank Goodness" and "Wonderful")
GODSPELL (ukelele on "All For The Best")
PIPPIN (banjo on "War Is A Science" and "Glory" dance)
THE BOY FROM OZ (banjo on "When I Get My Name in Lights" and "Everything Old Is New Again")
AVENUE Q (banjo on part of "It Sucks To Be Me," "If You Were Gay," and "My Girlfriend Who Lives In Canada")
"How could she just suddenly, completely disappear into thin water?" - The Little Mermaid