Complex sentence: He is an acknowledged expert on healthy vocal production for solo and choral singing (1) and the effect of conducting gesture on vocalists and instrumentalists, and his choirs are known and praised for their warm, natural, expressive and efficient sound.
Split into simpler sentences: He is an acknowledged expert on healthy vocal production for solo and choral singing and the effect of conducting gesture on vocalists and instrumentalists (1). His choirs are known and praised for their warm, natural, expressive and efficient sound.