How to use Audacity to record off of web pages?

I have Windows 7. The only main reason I want Audacity and only Audacity is for the face that it can change the pitch of the song. I'm quite new to using this program so I really do not know. I would like to play music on web pages (Like Playlist, Lala and Youtube) and for it to be recorded on the program. If anyone knows how to do this, I'd love to know.|||I doubt if Audacity has that capability. But, you can do it with SoundTap. Works just great for capturing streaming audio.