'Thirteen' is the thirteenth studio album by classic British prog band Soft Machine. The album of superlative new material, marks a fresh chapter in the group's 60-year history. Whilst the line-up of Soft Machine may have changed many times since the heady days of the late 1960s, the band's spirit of musical adventure, and the ease with which it freely avoids being pigeonholed has stayed a constant - as it moves from powerful progressive jazz rock to atmospheric psychedelia to free improvised jazz to ambient loop music. 'Thirteen' features legendary guitarist John Etheridge, who has been with the band over 50 years and is once again in superb form. Whilst all four members of the band contribute compositions, the album's main composer is saxophonist, flautist and keyboard player Theo Travis, who wrote six of the album's thirteen tracks. The newest member of the group is drummer and composer Asaf Sirkis. The album is incredibly broad in its breadth and scope. Tracks include "Open Road" a rocky track which sees the band soaring on all burners with fiery solos by both Etheridge and Travis; the ballad "Disappear", which starts with ethereal looped flutes and develops into a beautiful piano led and drum less miniature. "Turmoil", penned by bassist Fred Thelonious Baker, brims with deranged fuzz bass, manic solos and an almost unhinged clamour. "Daevid's Special Cuppa" sees a cameo by founder member Daevid Allen (his guitar part being recorded years earlier, and the track built around it). On 'Thirteen' Soft Machine has never sounded more adventurous.