No. 20; Late romantic, Classic FM friendly piece, though if you're a Classic FM devotee the chances are you've only ever heard the slow movement. I posted the start of the first movement.

Very large orchestra for this one. Composed in the late 1800's... normally

Da-da-da-da-DUM,
...da-da-da-da-DUM,
...da-da-da-da-da-da-da-DUM, da-dum.

I suspect Watty will get this one straight away...

um, sorry about the "normally" there, was going to write something else but deleted it and missed a word.

Um, sorry, this is number 23.

[rab] your number 20 is Rachmaninov's Piano Concerto number 2 in C minor and I claim my £5.