The tempo of the music is 120 beats per minute, & the tune is 58 seconds long. Therefore, Dottie does 120 foot taps per minute; however, 1 minute = 60 seconds, which means Dottie does 2 foot taps per second. Since the tune is 58 seconds long, she does a total of 116 foot taps when the tune's over!
Also, 58 seconds is 29/30 of a minute; multiplying the fraction by 120 beats per minute gives you the same correct answer!
Notice how exactly 4 seconds pass by when Dottie taps her feet 8 times(4 taps in a row per foot) at 2 foot taps per second. 1 second passes for each even-numbered foot tap!
© Derek Cumberbatch