Acollection of pitches arranged sequentially in ascending and descending order constitutes a:
a) scale.
b) triad.
c) chord.

Scale.

Explanation:

As the exercise briefly describes, a scale is a collection of sequentially arranged pitches is what makes a scale. Any musical notes ordered by a sequence is a scale, which is as well determined by the ascending or descending pitches. If the scale ascends is an ascending scale whereas if they descend its a descending scale.

answer; through play and social interaction;

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