 "These lines have often challenged modern singers, who have been unsure whether they are high tenor parts or are meant for falsettists".Contemporary vocal treatises, however, make clear that Purcell’s singers would have been trained to blend both methods of vocal production.In Purcell's choral music the situation is further complicated by the occasional appearance of more than one solo part designated "countertenor", but with a considerable difference in range and tessitura.