Rock out to a musical demonstration of math involved in constructing rhythms from groups of beats in this video from KQED. In the accompanying classroom activity, students consider how the note durations comprising a measure in 3/4 time relate to fractions that sum to 1. Then, they create and perform their own 3/4 measures comprised of quarter, eighth, and sixteenth notes. To get the most from the activity, students should have experience adding fractions with unlike denominator.