Just turn you favorite radio on in the background on your device (i.e. Pandora for instance), go to Gravitarium's menu* and tap the MIC icon in Audio to turn it ON - then simply use your preferred sticky dancing flow to sit back and relax as the particles swirl to the beat:
* Menu access: tap any corner or swipe up form the bottom of your screen
P.S. The all-time favorite is the dancing Energy Flow:
1.) Start with a fresh screen using the recycle icon in the bottom right corner of the menu.
2.) Tap in the proximity of 3 screen corners to make the animation wide.
3.) Control the Beat sensitivity in the Audio menu and particle flow Speed in the Options menu for a perfect mach to your particular music style!