The 12 gauge would probably work okay playing music, but it is technically too small for that much power / impedance, which I assume is going to be 2 ohms or less. If you were to do it properly, 10 gauge would be minimum for 2 ohms with as much current is going through the wire at 1700+ watts, and if you’re running 1-ohm 8 gauge. I'd admittedly run the 12 gauge if I already had it, and just double it up which makes it about 10 gauge. I'm cheap like that though and rather use stuff I already have.
Speaker wire usually doesn’t make any perceivable difference in the output unless it is insanely too small, but, you still can run too much current through it which equates to heat in the wire. With music this isn’t that big of a deal since it is often very dynamic, pauses, changes in impedance as it plays, so 12 gauge could work okay with no issues or loss in output, but with sinewaves, it’s pushing the wire a bit and better to just get the bigger wire. And of course the bigger wire never hurts in a larger install like this.
Others can add their input on what they would recommend.