In 1969 legendary jazz musician Miles Davis, his drummer Tony Williams, and Jimi goddamn Hendrix all thought to make a band after a year of jamming in a apartment. They had all the components necessary just needing a bassist, so Jimi Hendrix proposed legendary bassist, former Beetle, Paul McCartney to join. They all were cool for it and sent Paul a telegram asking him to join them. However Paul was vacationing in Scotland at the moment and turned them down.
Lets say Paul takes them up on the offer and potentially one of the greatest supergroups of all time becomes a reality. What happens next? How do they affect music? Could they stay together for a decent length of time?