We've been using Music for Little Mozarts since the spring with my then-barely five year old and three and a half year old daughters. They really like the stories and haven't lost interest in the books yet (and we're finishing the second one). I will say that it helps if there's a grown-up around that can play the accompaniment (gosh, wouldn't it be great if I could spell?), otherwise it could get dull. My girls LOVE playing with someone and it's the highlight of their week (if they practice like I ask, then once a week Daddy sits with them and plays). I've never seen the other one you're considering, but I recommend this one.