Sorry, my last comment was specifically in response to some of the posters here talking about RUS or 'the blue book'. From what I've gleaned it's a 'one size fits all' kind of affair and everyone sings the exact same songs - all together now - in the exact same way 'the book' has got it writ - which sounds thoroughly mind-numbing to me and not far off the sort of thing one might expect to find in an elderly folks home..
As for individuals using a prompt that's their business. But 'the blue book'? I dunno, but I reckon if it were in a novel it'd be subtitled "Joy Joy Nu-Song for Loyal Patriots!" and you'd have to take your blue pills before meeting together at the same time to sing the ministry's socially positive joy joy nu-songs together like good citizens!