What is the main idea behind creating this video using copyright protected characters?

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

What is jazz like today? 1 paragraph.

The three-movement symphony of sorrowful songs features a different text for each movement. its second movement (below) concerns the plight of a young polish prisoner seeking the protection of the queen of heaven. who is the composer of this piece