This is the companion to the Magnificat. Suggestions for organ registration are precisely that: as with the Magnificat, there are toccata-like passages which ought to be played on a separate manual. Sopranos and altos are occasionally asked to divide: these are shown by small notes. Where choir size makes this impracticable, these divisions are to be regarded as optional. The organ part is blank for bb. 33-35: if required, the choral parts can be doubled with soft registration. A clear break should be made between the end of the Nunc and the Doxology that follows. Metronome marks have been added to produce the effect the composer desires even though corresponding tempi are sometimes absent. There is more here: http://compositionmatters.wordpress.com/2012/10/30/nunc-dimittis/