However, from what we've seen so far via datamining on the PTR, your quest doesn't end when you create the boombox. You'll need tunes to fill the thing -- and there are a wide variety to choose from. Most city themes are included, as well as old favorites like Lament of the Highborne and the Karazhan Opera House music. Keep in mind that because all of the sounds are datamined material, there's no guarantee that these options will make it to live servers.
Given the sheer amount of music Blizzard has produced in conjunction with its games over the years, this is honestly a really nice way to bring all those great themes from the past back into relevance, and allow a little more customization as well. Future builds should fix any quest bugs and further reveal what we have to do to obtain all the tunes our hearts desire -- until then, I'm going to try and wrestle with the decision of what I want to hear while I'm hanging out with my followers and friends.