Polyphony and monophony in instruments harpejji and the Chapman stick). Multiphonics can be used with many regular wind instruments to produce two or more notes at once, although this is considered an extended technique. Explicitly polyphonic wind instruments are relatively rare, but do exist. The standard harmonica can easily produce several notes at once. Multichambered ocarinas are manufactured in a number of varieties, including double, triple, and quadruple ocarinas, which use multiple chambers to extend the ocarina's otherwise limited range, but also enable the musician to play more than one note simultaneously. Harmonic ocarinas are specifically designed for polyphony, and in these instruments the range
Owned-and-operated television stations in the United States in Green Bay, WFRV-TV (channel 5), and its satellite in Escanaba, Michigan, WJMN-TV (channel 3), to Liberty Media in exchange for common CBS stock held by Liberty Media; the sale of WFRV/WJMN closed on April 18, 2007. The Four Points transaction was approved by the FCC on November 21, 2007, and was finalized on January 10, 2008. In 2012, the Four Points stations were acquired by the Sinclair Broadcast Group; WFRV/WJMN was sold to the Nexstar Broadcasting Group in 2011. For much of the modern television era, NBC did not have an owned-and-operated station in Philadelphia. In 1955, NBC forced