At a molecular level, musical sound vibration can interact with our own vibrations in ways we may never understand. Music can be healing. Music can affect our moods and can stimulate or soothe us. Often native aboriginal music vibrates to the core of our being. I have played the Australian didgeridoo for a couple of years, and have used the unbelievable vibrations created by this ancient, simple instrument to tap into my own energy in new and exciting ways.
More modern music works as well - a well played violin can bring people to tears in seconds.
Mozart brings an audience to life - creating exhilaration out of nothing. Play with music while you are practicing your tai chi. Find sounds that create moods that work for you, and use them accordingly. Notice the dichotomy created using strong, powerful fast tempo music as you are flowing in your tai chi. Then try slow soothing music.