What musical instrument, widely used in rock and roll music, became the most popular?
a. synthesizer
b. piano
c. drums
d. guitar

What images are featured on the retangular panels along the sides the image above

Natural minor half steps between scale degrees 3 and 4; 7 and 8 harmonic minor half steps between scale degrees 2 and 3; 5 and 6 ascending melodic minor half steps between scale degrees 2 and 3; 5 and 6; 7 and 8 major half steps between scale degrees 2 and 3; 7 and 8

Using the correct order of operations, what does this formula equal? =(4-2)*6/2.