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The whistle is used by a leader in samba percussion groups to help catch the percussionists' attention. The traditional samba whistle has three tones, but as the size of the percussion section rose, pealess whistles became more popular due to their high pitch and their loud sound. The slide whistle (or swanee whistle) was a common instrument in some types of music,[which?] including being used at times in early Jazz,[4][5] and was popular as a musical effect in the early days of radio and television. The tin whistle (or penny whistle) is a 6 holed instruments with two octave range that is also used to make music. Pitch pipes are reed whistles used to help in tuning musical instruments and have been common since the 1850s. During the 1990s, it was common for whistles to be employed by the audiences at raves, allowing a level of interaction between the partygoer and the DJ. In fact, there were a series of raves during the late 1990s named "Whistle". Held at a nightclub named Shampoo in Philadelphia, the Whistle parties (raves) were held once annually, making each party a sequel to the one the year before.
Forrás: http://en.wikipedia.org/wiki/Whistle#Music