In this week's survey Derek Jéwell features an extract from KEITH EMERSON 'S first piano concerto, which is to be found. along with rock and jazz arrangements, on the recent album, Works, by EMERSON LAKE AND PALMER. The composer, in this case, plays piano, with the LONDON PHILHARMONIC ORCHESTRA; on other tracks from the same album, drummer CARL PALMER has the assistance of jazzman HARRY SOUTH and a big band. Apart from ELP. the remarkable vocal group, VOICE, and a new German band, LAKE, are also featured: records