What makes Fourth by Soft Machine notable?

'Fourth' is notable for its critical reception, being hailed as an essential work within the progressive rock genre. The album's experimentation helped cement Soft Machine's influence on subsequent acts in both the jazz and rock realms, contributing to the evolution of the Canterbury sound. By the time 'Fourth' was released in February 1971, Soft Machine had solidified their presence in the Canterbury scene, following their 1970 album 'Third'. This record marked a pivotal moment as they fully embraced jazz influences, transitioning from their earlier avant-garde roots and showcasing a more mature sound.