Fill in the blanks to complete the sentences. the spontaneous creation or variation on an established theme within an artistic work is known as . a rhythm that emphasizes the off or irregular beats is known as .

The spontaneous creation or variation on an established theme within an artistic work is known as improvisation.  A rhythm that emphasizes the off or irregular beats is known as syncopation.

Explanation:

Improvisation is considered an interpretive resource that demonstrates the spontaneity of the artist through the creation or spontaneous variation of a theme established within an artistic work. In music, syncopation is a rhythmic figure characterized by the execution of sound in a weak time, or weak part of time that extends to the strong time, or next strong part of time, creating a displacement of the rhythmic accentuation, in other words, is the rhythm that emphasizes the off or irregular beats.