Don't waste money
Im not sure why so many people liked this.
I bought it early on for my baby. She's now 7 months and I brought it out again. She she spun the wheels but its sooooo quiet & you need to spin so fast in order to get the slightest noise. As someone else mentioned the notes all practically sound the same as well.

My daughter likes to bang things anyway, not spin.

Just Ok
The piano is not what I expected a piano to be - it has rollers that turn instead of push down keys. It is very colorful but there is not much you could do with it. My 9-month old was bored with it in 5 minutes. Maybe it is better for a younger baby. Overall, it is just ok.

Not spetacular - just all right
My 7 month old would rather suck on the corner of it than actually play with it. The colored wheels spin causing the keys to "ding" - kind of like a xylophone without the mallets. But the "ding" is really pretty soft sounding so it just doesn't capture my son's attention like some of his other (louder) toys. And I usually keep the volume pretty low on those anyway, so that means this just barely makes any sound. It's just not that fun of a toy for him to play with.

perfect toy
I have been trying to find toys for my 7 month old that make some noise but are not too irritating for parents. Found it! Now I just wish that I had bought this 5 months ago. My seven month old just loves it and it took him no time at all to figure it out. It is really easy for him to use, the rolling is ideal for babies instead of the simple banging. And I can well imagine that this would suite a babies from maybe 2 to 3 months and up. As I said, wish I had bought it few months ago to get more lifetime out of it. On the negative. To my musical ear I wish they had used 8 notes and have them from e.g. C to C. The 5 notes don't really make a nice musical instrument. But then I guess it would have been too bulky. I guess you can't have it all. But so far the best music toy I have found for babies.

Excellent Easy Entertaining Toy!
This little Rainforest piano is so ideal for little hands that don't have great fine motor control yet. Gone are the days of hitting the Xylophone style bars with a beater. Now its all done with one bat of the hand. The wheels have a little pin on which as the wheel is rotated is pushed out with the centrifugal force hitting the corresponding xylophone note. There are five different notes. (please note it does not play whole tunes.)
My eight month old has had this since February and loves it. He is somewhat puzzled that he cant take the giraffe and the monkey off and spends ages trying to do so, and will bat at the wheels for quite some time to make the sounds. Another great idea from the Fisher Price Rainforest Range.