Wrong: there's guitar. Played by a local musician named Scotty Johnson, who played in the Finding Neverland orchestra at ART, and who I think played for Newsies when it was in Boston.
rcwr - of course you're right about guitars - can't really play rock 'n' roll without them. I specifically meant violins on "Will You Love Me Tomorrow."
I want to fix my comment because there's not just one guitarist -- there's also a guitarist who's part of the core touring band, Eric Stockton. And there's a bass player. And there's bass viol.
No violins, true. But the guitars do play in "Will You Love Me Tomorrow." I couldn't see the bass viol to see whether it was playing in that song too.