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.
Library of Congress. Uriah Stephens (1821-82) founded the Knights of Labor, the first national industrial union in the United States, in Philadelphia in December 1869 and led the organization until he resigned his post as Grand Master Workman in 1879.