Ayuda quiero un informe científico sobre cualquier cosa pero eso no es tan largo debido una que esta a la mano

Why were staff lines an important improvement to musical notation a. sl indicated rhythm b. sl indicated dynamics c. sl indicated pitch d. sl indicated meter

Need to answer this question on a discussion board post

Which would you practice to exercise all four of your left-hand fingers? a minor chord c major chord chromatic scale e minor pentatonic scale