Hi, I'm not sure if this is useful, but I've just discovered why there are 2 options for singing each (world adventures) song with another sim - one is to sing it romantically, and one is to sing it normally! Unfortunately it doesn't say which is which, so trial and error, by checking the message that pops up when mouse is over the to do action, is the go.
Anyway, just a tiny thing, but I find it useful to know whether I am wooing a sim with song or not.