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.
The Knights of Labor, the first national industrial union in the United States, was founded in Philadelphia on December 9, 1869, by Uriah Stephens (1821-82) and eight other Philadelphia garment cutters.