I think that the simple songs for babies are getting boring. They are on almost every toy. They are also very annoying when they make a "dog" or a "cat" or something else sing it. I personally think it could be something that adults enjoy and it could be a real recording. That would make toys much more interesting.
P.S. I really want Music of the Night (from the musical "Phantom of the Opera") to be on my baby sister's toys. I'm just obsessed with that song. 
Haha. What frustrates me most are those Kidz Bop CD's they constantly advertise on TV. I hate how they take good songs and turn them completely cheesy. -_-
Check out "See You on the Moon: Songs for Kids of All Ages":
http://www.amazon.com/gp/product/B000ENBNWC/sr=1-1/qid=1145783699/ref=sr_1_1/102-4914019-2704902?%5Fencoding=UTF8&s=music
It's a nice little compliation by some really notable Indie artists. yeah, I don't think babes have such a bestial perception of music ... I think a baby can already appreciate opera music, piano compositions, but not already some grindcore, it would tear his ears 
But that's dangerous anyway. It's proven that classical music, particularly Baroque, is beneficial to babies. Who's to say that more complex or hardcore music wouldn't damage a baby. I think I remember that being proven somewhere.
On that note, if the classical music thing was true, not saying that it isn't, then would't everyone use it on their babies? If that were the case, wouldn't everyone be smart? (barring parents that ignore facts\want the kid to be retarded)
just a thought...a late night thought at that...
i heard sometimes that pregnant mothers who used to listen to classical music bore a gifted child. i dont know how true this is, but so far i heard it many times already.
i could see classical music helping based on the mathematical harmonics that can be heard in it. I'd imagine the fewer the instruments or the clearer the melody, the better it would be (thus easier to follow 1 key + 2 up = a nice simple chord).
but ya, i think music on toys is just there as a distraction, to get the babies attention because the toy is making noises. I think any noise would be fine then, heh.
I think the best music for your babies is a band called Cannibal Corpse. With them your childrem will be happy and healthy
I just hope they put out some of new "They Might Be Giants" titles, great baby music which can be enjoyed by adults just as much. Frank Black of Pixies fame is under great influence from that band.
