When the music is playing, how can I draw a wave?
This will help you:
http://www.codeproject.com/KB/audio-video/SoundViewer.aspx
Here's a demo project that will allow you to visualize sound waves in C #:
You can draw a graph and change its pitch over time depending on the pitch, volume, or any combination you may wish. The standard is a change in period based on sound frequency and pitch in amplitude.