Hi
One of the most amusing or even outrageous musicals around the 1950s was Red Garters with Guy Mitchell and Rosemary Clooney.
It must count as a Western for the simple reason that it take place in a western town. It must count as a musical because both Guy Mitchell and Rosemary Clooney sing. It has a storyline, the scenary is just flats depicting a town with no backs.
A really strange film probably so bad it is good.
Regards
Arthur