Back in that day it was a real kick for some of the actors to sneak in a flash appearance in a comedy "short" often without the powers-that-be knowing about it. I seem to recall that the Three Stooges had some star-quality appearances in some of their "shorts" (all right, Knock it off you guys) and they also appeared in some films. I think one was a Clark Gable film. Can't remember.

Cartoonists of that day loved painting "then-Stars" into their works also. I remember my Mom telling me who the characters were supposed to be. You never see those cartoons any more as many are considered to be racist or not PC! or too violent! Well, that is a subject for another thread.

But as for a Frank Sinatra appearance? "aaaaaaaaaaah, Could be!" ( a la B. Bunny).