this song in three voices, based on one principal theme and have continuity and fresh meaning is the whole point of such developments.
also,this song adds greatly to the effect of the startling stretto in bars 27-28, and in bar 44 makes a bridge between the chromatically disguised bass entry of bar 43 and the final four-part stretto in descending thirds (bars 44-46). in this stretto (the enlarged converse of the three-part stretto in rising sixths, bars 33-34) the best way to make the crossing parts clear is to bring out the alto more than the soprano, and the bass more than the tenor.
the song as the developments and climaxes are obviously very sonorous, great care must be taken never to force the tone ; and it is well to use the stretti as occasions for a slight insistence of manner which may increase the volume of sound by easy stages. Legato, or (in big climaxes) its equivalent, stentato or portando, is required everywhere except for those commanding repeated notes with which the subject begins. the tempo is a very broad four in the bar ; not quite an eight.