What is the plural of crescendo?

The plural of crescendo is crescendos.

As in "the crescendos in these musical pieces are stunning".

I'm not convinced adding 's' make crescendo plural!

In English, with borrowed Words, we often simply add 's' to make a plural like: 'piano/pianos'. Whereas normally, when a Word ends in 'o' we add 'es' like 'potato/potatoes'. There is no definite rule.

With other Italian Words, we often follow the Italian rule by changing the 'o' to 'i' as in 'Paparazzi/Paparazzo', 'graffiti/graffito'.

Therefore, I'd say the plural of crescendo is crescendi.

As it is a borrowed Word, I'd say it could be acceptable to use 'crescendos', (it is now acceptable to use 'stadiums' rather than 'stadia' to make stadium plural. Or referendums/referenda etc) but a purist wouldn't.