There are seven, all of classical composers, including Mozart's "Eine Kliena Nacht Music" and "Rondo Alla Turk", Vivaldi's "Spring" from "The Seasons" and Rossini's " William Tell Overture. There is a Chopin piece, also.
It is not that quiet on loud, but not terribly loud either. You should not have to hold it to your ear on loud, although it is not as loud as many toys (which is why it is more tolerable to everyone else in the room or car who have to hear it over and over!)
Considering that Baby Einstein has already had a toy recalled for toxic levels of lead (blue block in their Discover & Play Color Blocks), even if they aren't listing the toxins in their toys directly, they are a suspect company. One boy was suspected of being poisoned by these blocks when no other lead-containing items were found in the house. Besides, lead, PVC, and BPA (which you probably get more from in canned foods anyway) aren't the only toxins in toys and other household objects. Many have toxic levels of antimony, bromine, barium (Melissa & Doug has had two recalls in Canada for this), cadmium, arsenic and mercury.
I mostly deny my kids the pleasure of putting any toys in their mouths excessively, but if you want to feel a bit safer about toys, try plugging individual toys/companies into HealthyToys.org or www.goodguide.com. You'll get a better feel for who has repeat offenses. I wouldn't trust anything a manufacturer tells you anyway. They have no intention of pulling dangerous toys or disclosing information unless they're forced to by law.
Saying that, we own this toy, as it was gifted before we knew what we know now. The kids love to dance to it. I consider it hazardous for the kids to put in their mouths. I imagine it's not doing a lot of damage just being held. And it does play pleasing music :)
It does take batteries. It comes with demo batteries installed but they don't last very long. It plays a tune and then stops unless you or baby hit the button again. If it's dropped onto a hard surface it usually stops playing, but if you hit the button it starts up again. Ours has been dropped a billion times onto concrete floors and is still going strong.