I did try streaming a backing track on my phone. The first one YouTube found was our very own Quist's blues in A! I reminded myself of how terrible I am at improvising, but the feature works well.

Also, I found out why it only took two days instead of the 5-8 they told me. Apparently if a Guitar Center nearby has it, it ships from there instead of from Musician's Friend's warehouses, so this came from down the road a half hour.