I am unsure what your online costs will be and what format your lessons will take, but I do have a question. Have you thought of incorporating a pay-per-song system? Speaking for myself, I would really like to have the option of learning a particular piece--or part of a piece--that I cannot find the music for, or am unable to figure out myself. Most of these pieces will be on the advanced level and relatively obscure to most people so I doubt they will be part of your regularly featured songs. I would not be looking for regular lessons per se, just for occasional help. Maybe others out there seek the same? Just curious..
Feel free to get outside the box here.