could anyone tell every method to recognise the key of a song? For example in Wild Horses I have G, Am, Bm, C, D, F. So, I think the key is G cause it's the first chord played and, except for F, the major chords are GCD which make the I IV V progression and the rest of the chords are played minor. Well, what I wrote is pretty confusing , but as I said before could anyone tell me every way to recognise the key of a song? I would be great if it is explained with a clear example.
thanks!