This is more a breakdown than a full detail tutorial. I want to give you an idea how you can animate a rigged character in After Effects with BeatEdit for After Effects. The bassist character we use here has been created by Tobias Hart aka 2biasMotion and has been rigged with Joysticks & Sliders and iExpressions.
In the breakdown we show how we animate the individual sliders and joysticks of the character rig step by step to create the final animation. We use the Beat Wiggle component of BeatEdit for all of it. A great thing about the beat wiggle are its randomness parameters. In contrast to simple looping animations, they allow you to create animations that fit very well to the music and still are not 100% regular or repetitive and and hence very natural.
Need more Details?
See this tutorial for a more detailed explanation (and using another character).