Of all the new British bands to emerge in the late 1970s, BRAND x is among the most fascinating. Formed by Genesis drummer, Phil Collins. as an alternative outlet for his music-making, it is now -minus Collins - a major band in its own right. Derek Jewell tonight plays from their new album. Masques. and looks at the latest work of two other important forces in rock today: BOSTON and LEO SAYER. Reggae is represented too, and he also notes the flood of jazz re-issues which mark the contemporary record scene with music by ERROLL GARNER. JEAN L'JC PONTY and LEE KONITZ. gramophone records