The album was successful, as it allowed new fans to catch up with early singles, particularly in the US where they had not been popular on initial release. Abrahams had heard that Ellis wanted Anderson to be the frontman and group leader, at his expense, and realised he was unlikely to have the majority share in songwriting.

There were a number of reasons given for his departure. The overall sound of the group at this time was described in the by Anderson in 1968 as 'a sort of progressive blues with a bit of jazz'.Following the album's release, Abrahams left the band in December to form his own group. In addition to original material, the album included the traditional 'Cat's Squirrel', which highlighted Abrahams' blues-rock style, while the -penned jazz piece 'Serenade to a Cuckoo' gave Anderson a showcase for his growing talents on the flute.

Cornick recalled, 'from that moment on, we were a big band'.The group recorded their first album, between June and August 1968, and it was released in October, reaching number 10 in the charts. The band have since claimed that the success at Sunbury was a result of their persistent touring, which had generated a grassroots following who had all assembled at the festival and encouraged the rest of the audience. Literally every night I walked onstage was a flute lesson.The group's first major break occurred at the at in August 1968, where the band drew a rapturous reception and positive reviews in the music press.

Jethro tull live in essen 1972