Late night extra Royal Albert Hall The Soft Machine Anybody going to the late night Prom on Thursday hoping to enjoy some piquant moments with a pop group on the bill was probably disappointed. The whole concert was a successful exercise in boundary-breaking and the Soft Machine's excellent musicianship merely extended frontiers that had already been breached by a mesmeric per- formance of Terry Riley's Key- board Studies from Intermodu- lation (which included the Soft Machine's own organist, Mike Ratledge) and Tim Souster's Triple Music II. The latter set the tone of informality that characterized the whole even- ing with the B.B.C. Symphony Orchestra playing in three areas of the hall and dressed in mufti. Enjoying the subtleties of Tim Souster's work was like watch- ing a triangular tennis match. This must have been the first Prom where the musicians' in- struments were set up by " roadies " and the Soft Machine treated the concert as a well attended gig. Labels no longer have much meaning in the world of progressive rock or jazz and the four man group fluently moved from savage sheets of sound to delicate phrasing where Elton Dean's remarkable alto leads were quietly shadowed by Hugh Hopper's bass guitar and Mike Ratledge on the electronic organ. The bare chested drum- mer Robert Wyatt demonstrated that excellence in drumming is not, as so many rock drummers believe today, an exact reflexion of a solo's duration. His frenzied scat-singing was the nearest the group approached to vocals during the single number that occupied their whole perform- ance. The Soft Machine are one of the few groups able to do their musical structures justice in both live concerts and on records. Although a member of the group has recently said "you get five times your money's worth if you listen to us smashed ". I doubt if the Prom audience was affected by this advice. Richard Gilbert Late night extra