On Friday’s episode of the CW musical comedy “Crazy Ex-Girlfriend,” the lovelorn title character Rebecca (Rachel Bloom) attends a bar mitzvah with Josh, her ex-boyfriend, that’s presided over by her childhood rabbi. Nothing strange there. But when it’s the Tony Award-winning actress Patti LuPone under the skullcap — with the Tony nominee Tovah Feldshuh slaying an imaginary hora as Rebecca’s mother — well, that’s where things start to get funny.

In the episode, Ms. LuPone and Ms. Feldshuh lead a klezmer-crazy musical number called “Remember That We Suffered,” about a Jewish taste for basking in horrors past. Much to Rebecca’s obvious discomfort, the lyrics at the top of the song set the cheerily misfortunate mood right away:

Nights like these are filled with glee

Noshing, dancing, singing, wee!

But we sing in a minor key

To remember that we suffered!

Are there any Mel Brooks-style Holocaust references that make Rebecca cringe in horror? How’s this:

The sweet and the bitter!

Remember that we suffered!

Streisand and Hitler!

Remember that we suffered!

Does the D.J. do a wave-’em-like-you-just-don’t-care call-out to the assembled dancers? It wouldn’t be a bar mitzvah without it:

When I say we, you say suffer!

We!

Suffer!

We!

Suffer!

What’s so funny about suffering? Ms. LuPone recently spoke about the episode, called “Will Scarsdale Like Josh’s Shayna Punim?” (Translation: “Will Scarsdale Like Josh’s Pretty Face,” for those of you rusty on your Yiddish). Here are edited excerpts from the conversation.

First things first, Patti. Are you Jewish?

I’m Italian Catholic. I’m binge-watching “Transparent” now and I should have gotten lessons on how to play the rabbi. I think all religions are the same.

How did this role come to you?

It’s a great show. My son turned me on to it. I happened to go out to California, and said to my manager, I love “Crazy Ex-Girlfriend.” I think it’s a very inventive, creative show. I’d like to see Rabbi Shari come back.