For ten points , name this musical symbol, the opposite of a diminuendo, drawn as two slanted lines connected on the left and meaning "get gradually louder."
The Mannheim school is famous for its whole-orchestra type of these, and a seventeen minute long one of these is found in Ravel's orchestral composition, Boléro. One of these signs followed by its opposite is sometimes referred to as a (*) "hairpin," in reference to its shape. For ten points , name this musical symbol, the opposite of a diminuendo, drawn as two slanted lines connected on the left and meaning "get gradually louder."
The Mannheim school is famous for its whole-orchestra type of these, and a seventeen minute long one of these is found in Ravel's orchestral composition, Boléro.
{Crescendo}