Bloodbrothers is tragic all right, but not all that good. Maybe it is just me, but when a show tells you how it is going to end at the very beginning, that isn't very solid dramaturgy, you know?
It is easy to sit through and everything fits, it just isn't that imperative.
The Boys From Syracuse (original NOT the recent revise) is a lot better. However it would only be tragic if you forgot it was a comedy.
As Edmund Gwenn said on his deathbed, "Dying is easy. Comedy is hard."
"If my life weren't funny, it would just be true. And that would be unacceptable."
--Carrie Fisher