This skill has 3 usage levels: 1. 180 free backing tracks - Use your own guitar and/or amp to play along. 2. Free backing tracks + effects processing - Plug into your Thingamagig device and this skill will set your tones. 3. Electric guitar karaoke! - You rock out to famous hits while Thingamagig controls your mix, tones, effects and loops automatically. Try it! it's surprisingly fun. (Sub required, but it's under a dollar/mo.)