The difference between gaming headsets and music headsets is that gaming headsets provide higher gaming audio quality (3D sound) than music headsets. Gaming headsets are also heavier and bulkier than music headsets, so they're usually not used outside of gaming.
Main differences: bass performance, surround sound technology (3D, 7.1), noise cancellation, audio quality, portability.
Bass and surround sound (3D, 7.1) is an essential function of headphones. Gamers want to hear the full performance of their headset, and solid bass brings out in detail convincing explosions, enemy footsteps and sounds coming from all directions. It gives the feel of the game and helps make the game more realistic. That's what gaming headsets are for. Most music headphones don't always favor bass. Instead, they focus on a full-range performance of instruments and vocals that fall on different ends of the audio spectrum. In short, the music headphones have a balanced all-round performance.