It marked the band's comeback after a brief disbandment, and peaked at number 5 on the Billboard Top LPs chart, making it their highest-charting album in the US,[2] and has been certified a gold record by the RIAA.

In 1969, Steve Winwood joined the supergroup Blind Faith, while drummer and lyricist Jim Capaldi and woodwinds player Chris Wood turned to session work.

He recorded two tracks with producer Guy Stevens, "Stranger to Himself" and "Every Mother's Son", but yearned for like-minded musicians to accompany, inviting Wood and Capaldi to join him.

Whereas previous Traffic albums had been dominated by more concise song structures, John Barleycorn saw the group develop into a looser, jam-oriented progressive rock and jazz fusion style, setting the tone for their subsequent output in the 1970s.

The album was reissued for compact disc in the UK on 1 November 1999, with five bonus tracks, including three recorded in concert from the Fillmore East in New York City.

[8] Village Voice critic Robert Christgau said the departure of Mason hurt Traffic's songwriting on the album, leaving the band to depend on Winwood's "feckless improvised rock, or is it folksong-based jazz?