I must say, looking at the piece and having been a musician of sorts, that looks like one rather difficult piece of music.

. It's pretty slow, but when you get to the 32nd notes, the timing's a bit tricky; and it goes up to F7 (hence all the ledger lines ).

Here's the link. Heifetz - Beethoven Romance No. 2 in F Major
I can't play it anywhere near as well, but hey

I think it works fine at f/2.8.

Getting around to looking at the albums...I agree with Karen since if you went to 5.6, too much of the background might be in focus too and then be too busy.