What are the vocal ranges of our fave singers: Kowalski, Blowhole, Skipper, and Julien.

If by vocal ranges you mean what choral part they can/could sing as then Kowalski would be a baritone, Blowhole as a tenor, Skipper a baritone, and Julien is a inbetween but he would probably sing tenor. Now, if you mean specific vocal range of notes; that would require sheet music for each song each character sung. Maybe I'll do some searching... Hope this helps!