I've seen this sheet music candles via Pinterest and somehow, it gave me an idea that this could be a nice housewarming gift especially for the newly weds. You could choose any romantic song you like, better yet the couple's theme song and have it printed with the corresponding musical notes. Best for candles of different sizes. This could also be a gift to a friend who is into music. Of course, you may prefer to give what musicians friend used but in case you are on a tight budget and you want to come up with a more personalized gift, then I think this could be a nice option. :)
Actually, I prefer to give DIY gifts because it shows how creative you are and create that impression that you are not only giving them a plain gift but a gift of your time, as well.