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.
Puddlers founded the first trade union in the iron and steel industry, the Sons of Vulcan, in Pittsburgh in 1858. In 1876, this union merged with three other labor organizations to form the Amalgamated Association of Iron and Steel Workers.