It might just be a generational discrepancy here, but HSM didn't create a concept as much as they rode down the paths of Grease and Fame (that was both a movie and a weekly television program). Glee is the next in a progression of musical school concepts, but this time it's tongue-in-cheek rather than taking itself so seriously or being primarily tween-targeted. Glee is its own thing. Of course, HSM made the idea popular to a modern audience. Still, I find Glee the answer to HSM rather than an extension of it.