A semitone, also called a half step or a half tone, is the smallest musical interval commonly used in Western tonal music, and it is considered the most dissonant when sounded harmonically. It is defined as the interval between two adjacent notes in a 12-tone scale (e.g. from C to C â¯).
The National Labor Union. The first large-scale U.S. union was the National Labor Union, founded in 1866 to organize skilled and unskilled laborers, farmers, and factory workers.
Under his leadership, the AFL became the largest and most influential labor federation in the world. It grew from a marginal association of 50,000 in 1886 to an established organization of nearly 3 million in 1924 that had won a permanent place in American society.