Although Ian Anderson had different ideas for the next release and began to steer the band away from the blues focus leaving Abrahams at odds with Anderson's vision for the future. A much used phrase at the time for anyone leaving a group was "musical differences", which usually meant an argument over who had the power.
Abrahams' obvious talent and reputation ensured he was going to follow his own path and formed one of the formative progressive groups in 1969 much around the same time as bands like King Crimson, and then ELP, etc. were attracting large audiences. The much underrated Blodwyn Pig released just two albums but were also one of the first of the new "prog" bands to actually appear in the pop charts.
After Blodwyn Pig, Abrahams was to continue solo with occasional returns to Tull reunions and one off groups from the Blodwyn Pig years. In recent years his health hasn't been good. Good luck Mick and happy birthday.
Here's Blodwyn Pig in peak form with "Same Old-Story" appearing on Top Of The Pops in 1970.
Warning : appearance by DJ Jimmy Saville may cause nausea.