While John Mayall is pushing eighty, has close to fifty years on the road as a full time musician and continues to add to an already extensive discography, that's probably the result of financial necessity rather than choice. Musicians tend not to have superannuation and health insurance, and incidents like the house fire in 1979 that took out his music collection and archives, as well as a collection of historic pornography dating back to the 13th century suggest that his investment decisions haven't always turned out for the best.
Mayall is best known for those few years in the late sixties when the albums he recorded with The Bluesbreakers regularly hit the Top 10 of the British album charts. Much of that success was, of course, due to the succession of killer guitarists he managed to enlist for a busy schedule around a fairly active blues club circuit.
When The Yardbirds veered off in directions that weren't compatible with his then-blues purist soul (cue: For Your Love) Mayall provided Eric Clapton with the gig that prompted the Clapton is God graffiti around the various blues-friendly venues across the British Isles.
Clapton headed off to form Cream with Jack Bruce and Ginger Baker after a music magazine poll identified the trio as the pick of British instrumentalists and Mayall had a ready-made replacement for him in Peter Green, who'd filled the slot during Clapton's three month Greek excursion towards the end of 1965.
Green's tenure on the Mayall treadmill lasted from 17 July 1966 until 15 June the following year, when he left to form Fleetwood Mac, and he was replaced by a teenaged Mick Taylor, the longest-serving of the great guitarist trio, who lasted close to two years before he went on the join the Rolling Stones.
As far as the recordings go, you can reduce the early Mayall albums to an almost essential handful by omitting the pre-Clapton live John Mayall Plays John Mayall, the solo in the studio The Blues Alone (both of which appear to be available on CD and iTunes) and the two live official bootleg before the category was invented volumes called Diary of a Band, which still managed to sneak into the British album charts despite sound quality that was on the ordinary side of ordinary.