A whistle or call is a simple aerophone, an instrument which produces sound from a stream of forced air. It may be mouth-operated, or powered by air pressure, steam, or other means. Whistles vary in size from a small slide whistle or nose flute type to a large multi-piped church organ.

The whistle has its roots dating back to ancient China, where night watchmen would blow into the tops of acorns to alert the towns to invading Mongolians.^{[citation needed]} In ancient Egypt two blades of the papyrus plant along the Nile river were held together in between the palms. By blowing into the palms the papyrus leaves would make a loud vibrant sound.^{[citation needed]}

Many types exist, small mouth blown whistles for various functions from toys to hunting using bird and fowl calls type whistles, to professional whistles as police, boatswain's pipe, military, sports whistles (also called pea whistles), to much larger steam or air preasure operated ones as train whistles, which are steam whistles specifically designed for use on locomotives and ships. Although almost all whistles have some musical character, common whistles are not usually considered musical instruments, since they cannot play a melody, unless used as a – very shrill and loud – noise and rhythm instrument. However, musical whistles exist, including various 2-octave musical instruments known as tin whistles (sometimes called pennywhistles or low whistles), as well as the calliope (an array of separately actuable steam whistles), organ pipes and the recorder. Pea whistles are used in jazz and Latin music for rhythm, much as a percussion instrument is; children often use them as a toy music instrument. There is also a more diverse type of whistle used for giving commands to sheepdogs at work, which can emit almost any tone the shepherd wishes, in order to signal different commands. This whistle is known as a shepherd's whistle.

Tramar Dillard (born December 16, 1979) better known by his stage name Flo Rida (pronounced  /floʊ ˈraɪdə/), is an American rapper. He released his debut album, Mail on Sunday, in March 2008. His debut single "Low", featuring T-Pain, was a No. 1 hit for ten weeks in United States in early 2008. Two other singles resulted from Mail on Sunday: "Elevator" and "In the Ayer". In 2009, his second album R.O.O.T.S. was released; its most successful single "Right Round" was at the top of the Hot 100 for six weeks. Since then, he has released his third studio album titled Only One Flo (Part 1), which will see a sequel titled Wild Ones.

Paul Stastny (born December 27, 1985) is an American professional ice hockey center, an alternate captain for the Colorado Avalanche of the National Hockey League (NHL). Of Slovak lineage, Stastny is the son of Hockey Hall of Famer Peter Stastny, who played for the Avalanche's predecessor, the Quebec Nordiques. Paul's older brother Yan has played for the Boston Bruins, the Edmonton Oilers, the St. Louis Blues and the Vancouver Canucks, and his uncles Anton and Marian Stastny both played in the NHL during the 1980s, also for the Nordiques franchise.

Stastny began his junior hockey career with the River City Lancers of the United States Hockey League before moving to the University of Denver Pioneers in 2004. He won the NCAA Men's Ice Hockey Championship in his first season playing for the Pioneers. He remained at the University of Denver for one more season. He signed a contract with the Avalanche before the 2006–07 NHL season, scored 78 points in 82 games in his rookie season and was nominated for the Calder Memorial Trophy. In 2007–08 he was named to his first NHL All-Star Game, but didn't play because of an appendectomy. As a dual citizen, Stastny has chosen to play for the United States in international hockey competitions, which have included the 2004 Viking Cup, the 2007 IIHF World Championship, and the 2010 Winter Olympics.

Lindy Cameron Ruff (born February 17, 1960) is the head coach of the Buffalo Sabres of the National Hockey League. Ruff played in the NHL for the Sabres and New York Rangers as a left winger/defenceman. Currently, he is the longest-tenured head coach in the NHL.

Ruff was chosen in the second round, 32nd overall of the 1979 NHL Entry Draft. He played for the Buffalo Sabres and New York Rangers. Ruff gained a reputation as a player for his toughness, character and hard work on the ice. An illustration of this came in a May 10, 1980 playoff game against the New York Islanders where opposing goaltender Billy Smith struck Ruff with his stick as he passed in front of his net. Ruff got up, skated back to the goaltender and tackled him.

Ruff played most of his NHL career for the Sabres, serving as captain of the team for nearly three years, but he was traded to the Rangers at the 1989 NHL trade deadline in exchange for a draft pick. The Sabres would use that pick to select Richard Smehlik, who would later play for several years under Ruff.

Cameron Jibril Thomaz (born September 8, 1987), better known by the stage name Wiz Khalifa, is an American rapper. He released his debut album, Show and Prove, in 2006, and signed to Warner Bros. Records in 2007. His Eurodance-influenced single, "Say Yeah", received urban radio airplay, charting on the Rhythmic Top 40 and Hot Rap Tracks charts in 2008. Khalifa parted with Warner Bros. and released his second album, Deal or No Deal, in November 2009. He released the mixtape Kush and Orange Juice as a free download in April 2010; he then signed with Atlantic Records. He is also well known for his debut single for Atlantic, "Black and Yellow", which peaked at number 1 on the Billboard Hot 100. His debut album for the label, Rolling Papers, was released on March 29, 2011.

Khalifa was born on September 8, 1987 to a mother and a father serving in the military. His parents divorced when Khalifa was about three years old. His parents' military service caused him to move regularly: Khalifa lived in Germany, the United Kingdom, and Japan before settling in Pittsburgh where he attended Taylor Allderdice High School.