I reckon something they could actually do is retheme HRRR to some of Universal's iconic film music so that you could listen to Happy by Pharell Williams or the Back to the Future music, for example. They could really capitalise on the nostalgia. Or they could retheme it to a single IP. If they wanted to do an Illuminations IP, as the rest of the surrounding area seems to be heading that way, I reckon Sing could be a good fit. I mean as it's a music theme, although I do think HRRR is a tad too big to be Sing-themed. I suppose it's no more stupid than retheming California Screamin' to the Incredibles, though. Alternatively, they could just expand on HRRR's existing theme of making a music video. They could theme the queue with cameras, lighting rigs and production stuff, sort of like Rock'n'Roller Coaster at Disneyland Paris. I think that's probably the most likely option if they did want to overhaul it.