I moved the keyboard to the left and put it in shadow. This works much better and keeps the emphasis off the white keys. I also placed the sheet music on the table for the same reason.
What bothers me most about this arrangement is the repetition of the gong shape in the tambourine. I'll have to work on this. Meanwhile the items on the right are quite jumbled, but it's a start.
I think with a bare minimum of tweaking, the left side will stay basically the same. I'm having a difficult time squeezing everything into the 18 x 24 space.