its the one Amanda is practicing for her recital but because she has a block in her brain she keeps messing it up. In the episode electric kiss it can be heard at

4:48 - Kyle listens to amanda play while the family have breakfast (but its only briefly heard)
6:41- Kyle leaves amandas house and she starts to practice
11:47 - Kyle eves drops on amanda from his bedroom
13:25 - scene where amanda practices but messes it up
19:07 - Amanda practices in a big hall with kyle watching and jessie soon enters

It isnt Pacabell Cannon in D and
it isnt Sonata for Piano No. 8 "Pathetique": Adagio cantabile by Beethoven.

Its such a beautiful tune I hope someone can help me out .this is it on youtube but where can i download it. just watched it on youtube here