Some composers are known mainly for a single piece, and this morning Rob Cowan delves deeper into the repertoire by such eminent figures Pachelbel, Dukas and Albinoni, to discover more of their range and variety as writers. Plus there's this morning's cantata by J S Bach, BWV 70: Wachet! betet! betet! wachet! (Watch! Pray! Pray! Watch!).