Ballrooms and slow dancing

I kind of hope they link it to an object somehow but not sure how they can... like if a radio is playing on a certain station, or someone is playing a musical instrument (or maybe when we can set up some sorts of bands). It sounds complicated no matter how you look at it.
I guess we could decide just to do it with our own sims but I'd like the dance to match the music. Besides it would be weird if sims are autonomously doing very wrong dance types outside of our control to music.