Sentence:  Also , it should be noted that the polytonal freedom of his melodies and harmonic modulations , the brilliant orchestrations , the adroitness for evading the heaviness of figured bass , the skill in florid counterpoint were not lost in his mature output , even in the spectacular historical dramas of the stage and cinema , where a large , dramatic canvas of sound was <WSD>required</WSD> . 
Meaning of the word marked with <WSD> tags:  required by rule