What would you do?
I've been mulling this over and over because it's a bit like a photographic chess problem. White to play, mate in three...
Were it me, I think I'd probably forgo the depth of field and break the rules about defocussed foregrounds. I'd aim to get the simplest possible outline of the guy with the mohawk and send it to a nice blurry bokeh, whilst catching a beautifully razor sharp image of the musician in mid phrase.
Although you could have used live view and held the camera up, this buggers up your focus efficiency so I'd definitely have been scouting around for something to stand on to get me a nice, clear view of the stage. Whilst your brief was to get them in the frame, I'd not want to be shooting *through* the punters in front of me, but rather slightly more *over* them. I'd definitely have been on tiptoe, anyway.
ISO 400-800 is probably where you needed to be. Unless you're shooting some kind of uber-wunder-camera, ISO1600 is usually a bit crap (well, I don't like pushing it that high on my Nikons). Better still would have been a nifty fifty and f/2.