One finds on YouTube, a lot of video clips from amateur productions of great musicals. Usually when I click to view one, I get a vivid reminder of the difference between an amateur performance and a professional one.
There are exceptions. Here's "Jubilation T. Cornpone" from Li'l Abner, as performed at Countryside High School. My Googling suggests the school's in Clearwater, Florida and I think the name of the gent playing Marryin' Sam is Nathan Daugherty. It's not a Broadway-quality job but it strikes me a whole lot better than high school. It's also a nice reminder of why this show is so popular with schools and community groups but never gets a New York revival. Reason: It requires a big cast, which makes it expensive when you have to pay actors. On the other hand, if they're not getting paid, you can fill the stage with bodies so all their friends and relatives will fill the audience.
While I was surfing around to find some info, I came across this article about a way in which the director gave the students a special bit of education. She got the original Abner, Peter Palmer, to come in and talk to the cast. It seems to have done some good…