For 3 Bb Clarinets and 1 Bass Clarinet, 'Mercy' is an obsessively expressive Adagio (so to say, a Samuel Barber's equivalent for Woodwinds) with a homophonic texture, like a four part chorale. Rhythmically, this piece offers no problems. While the first part requires more experienced players, parts 2, 3 and 4 are relatively easy to play. Most groups would be able to master this piece after only a couple of rehearsals.
Some would say that mercy is a virtue, others (following Nietzsche) that it is a weakness. Do not seek in this piece a one-to-one musical transcription of merciful feelings, but rather concentrate on the smoothness and tender sound quality associated with it. Rather than 'pity', mercy is about empathy, togetherness and support - this attitude can also show while performing music.