What kind of a role is this? I know that he's a Follies owner and that he's in his 50's-60's, but what else is notable about him? What role does he play in the story? Does he have any songs?

Bela Zangler is a great character role! He is a promiscuous man who is vying for a relationship with Tess, the follies choreographer. The man has a thick Hungarian accent. The role he plays in the story intertwines with that of Bobby Child: Bobby is desperate for a role in one of Zangler's shows, and after being dejected, decides to pretend to be Zangler in order to put on a show to save a theater in Deadrock, Nevada. All goes swimmingly until Bobby as Zangler falls in love with Polly, the daughter of the theater's owner, and then the real Zangler shows up! Bela Zangler sings a duet with Bobby, titled 'What Causes That?' The genius of this song is that Bobby and Zangler are both incredibly drunk, and, with Bobby disguised still as Zangler, do not realize that they are looking at different people, but rather think that they are looking at themselves in the mirror. Hilarity ensues as the blocking of both characters are mirror images, and witty dialogue makes the laughs even more robust! Zangler is a fabulous part, and, if played well, can really steal the show.

He needs to somewhat physically resemble Bobby (height/frame). He has only one song "What Causes That", sung with Bobby in the big drunk 'mirror' scene.

It's a pretty comedic role.

Yes, and he only speaks in an Eastern European (I wanna say Hungarian to be exact) accent throughout the show. He can steal the entire show if done well