My father would say, 'Play a scale,' and I'd play one and he'd say, 'What about the rest? There must be one above,' so we'd figure them out. I'd start the scale on the root of the chord and I'd go as far as my hand would reach without going out of position, say, five frets, and then I'd go all the way back. So when ! practised I'd start right away on scales. As well as the usual ones, I'd play whole tone scales, diminished, dominant sevenths, and chromatic scales. Every chord form, all the way up, and this took an hour.