When listening to music on PC, I use a Chinese mp3 player called TTPlayer. The main feature of TTPlayer is it display lyrics that synced with the music.
Searching for a web equivalent, the closest thing i found is this. But it has issues, for me anyway, i.e. play only one song, no play/pause control, can't scroll back, can't replay, use an unfamiliar animation framework. So I look at the code and come up with my own. The player is based on soundmanager2 demo code. It use jquery and jquery scrollto plugin.
The demo is at: http://wensheng.com/code/sm_lyrics/
The code can be downloaded here.