Think of ''A Grand Chorus'' at Westminster Abbey - the voices of massed choirs, as heard in Handel's Messiah or in the pomp and pageantry of the Coronation Services. But there's another Grand Chorus heard in the Abbey - the 6907 pipes of the 131 stops at the organ, spread over five keyboards and foot-pedals. Whatever the occasion, the Abbey organ is played - from the daily sung services to those spectacular outgoing voluntaries we have heard at so many national and royal events. On this recording, we bring you organ music across four centuries, much of which has close associations with the Abbey