Look at people who change for their own stimulation
UK viewers may have seen Saturday night's BBC documentary 'Robert Plant: By Myself' which explored his career following Led Zepplin and it's numerous fascinating musical partnerships.
Along with Phil Collins, a collaborator Peter and Robert have in common is Justin Adams, who has worked extensively with both Real World Records and WOMAD. Justin's also a long standing guitarist and collaborator with Robert. In 2009 at WOMAD Abu Dhabi Justin Adams and Juldeh Camara took to the stage together in an extraordinary joint performance with Robert Plant.