Relevant to the OP's example, "Meeskite" was sung by Herr Schultz in the original production of Cabaret but hasn't been seen in a major production for decades. I sang it when I played Herr Schultz in college, and I thought it was a fun song and an effective way to alert Ernst Ludwig to the fact that Schultz is Jewish, but I accept the fact that the creators were willing to let it go in the interest of a leaner show.