A Joke in Choir

11-yr-old girl, thrilled that the school is now BYOT (Bring Your Own Technology).

Girl: Oh, in choir this morning, Mrs S told a really funny joke!...
Me: Ooh, what was it?
Girl [pauses]: Um... [looks sheepish] I was ... uh... looking at ... something... on my iPad... and kinda ... didn't hear it.
Me: I.. see...
Girl: Well, it was about this girl, and she's singing something with so - la - mi and I think it's her mum who's wondering why she's singing about salami... You know, solami/salami...? 

I should ask Mrs S what the actual joke was.