Brian,
That was a very good interpretation of Mac The Knife. Although to be honest, this is not really 'my kind of music'.
I prefer 'straight harmony'. Here is a clip from the Barbershop Harmony Society. Directed by Lori Lyford, THE TREBLEMAKERS of Chandler (Arizona) High School join international quartet medalists MAIN STREET in a delightful performance of "Lida Rose/Will I Ever Tell You" from the film The Music Man.
Wouldn't life be boring if we were all the same?
Hugh