Than what appears on the cover.
It's drawn in Nagae Tomomi's later style, which is cute, yet mature. Even though the male lead seems like a colossal jerk in the beginning, you later realize that it's because this is all written in her point of view. Her disappointment, therefore, strikes very sharply, but the comedy makes up for that. Much of the misunderstanding is cleared up in the first few chapters, so I'd give it a try if you like music with a healthy side of romance.
However, this is not like Nodame Cantabile. Nodame is definitely more mature, dealing with deeper themes, and infinitely more music based. But the cuteness of this manga cannot be ignored. What it lacks in any sort of realism is made up by the charm of each character (though there are only 3).
On a personal note, I love the way the author characterized Chopin. Considering the overall feel of the manga, I wasn't really expecting anything serious.
It's a shoujo manga, and a really, really fluffy one at that.