I did music right through til 18 and really enjoyed it. my parents never made me practise though. I learnt that I had to practise if I wanted to get better and join things like the district band. why not let them learn that? and let them give up if they want to - they might well realise they miss it and take it up again. once anything becomes about a struggle of will that is all it ends up being about - in my experience at least (sigh). if you want music to be fun for them, then have fun yourself with music, go to concerts, play at home, have friends round to play, dance around in the kitchen?.etc. or take up an instrument yourself and join them at practice times. you don't say how old your kids are though. are they old enough to have a conversation about why they don't want to practise, or even if they are on the right instrument. I hated piano lessons but loved orchestra instruments. my only regret is that i ended up on the kind of instrument you can only play in an orchestra so i now don't do anything - whereas if i had learnt something a bit more folky or the guitar I'm sure I would have carried on playing informally. or why not just have a TV limit, so they are forced to do something else anyway!