Since Frieda is Morty's sister and we saw Morty himself sing towards the end of the series (when he was played by Steve Lawrence), I guess the Fines are just naturally musically inclined
Wait, so Fran Fine (Fran Drescher) met Fran Drescher who plays a nanny in a show similar to the one we´re watching? Sounds like a 4th Wall break and Crossover combined.
Speaking of clips on the Nanny which have never appeared in syndication, does anyone remember on the episode where Fran temporarily quits and ends up working at a department store when C.C. runs out of the dressing room and trips after Maxwell makes the announcement over the intercom? I remember seeing it when it first aired but it's never appeared on syndication. I know it exists because right before the scene cuts to black you can hear C.C. scream "NO!!!".