This online guitar tutor works from screenshots and photos, and it never touches your file or your instrument. The limit is said out loud because it is the method: it cannot hear you play. It reads a photo of your fretting hand, the tab or chord chart on your screen, your tuner reading, and what you report in words, such as which string buzzes or where the change falls apart.
A session is a loop. You show the state, it gives exactly one action, you do it, you show it again: what I see, do this, send the next photo. It knows what to look at, the thumb behind the neck, the fingertip just behind the fret wire, about 3 to 5 mm of pick showing, and the five beginner mistakes a photo gives away. You get an interface map of the instrument, the session protocol, and a first lesson arc from tuning to a full song. If anything hurts, it stops and sends you to a teacher or a doctor.
The same file works in Claude, ChatGPT and Gemini. Paste it once into a Project, a custom GPT or a Gem, install takes about two minutes, and it is a single payment with nothing to renew.