Conversation so far:
what happened to the incredible string band in 1971?
The band continued to tour and record.
Rose Simpson left in 1971 and was replaced by Malcolm Le Maistre.
why did he leave?
Mike Heron took time out to record a well-received solo album.
was he successful?
Mike Heron took time out to record a well-received solo album, Smiling Men with Bad Reputations.
did he return to the band?
Mike Heron took time out to record a well-received solo album, Smiling Men with Bad Reputations.
was that album successful?
CANNOTANSWER.
Are there any other interesting aspects about this article?
Their final albums for Island were received disappointingly, and the label dropped them in 1974.
By then, disagreements between Williamson and Heron.

Question: what wree their disagreements?
Self-contained rewrite: what were the disagreements between Williamson and Heron?