Slide whistle

A slide whistle (variously known as a swanee or swannee whistle, lotos flute piston flute, or jazz flute) is a wind instrument consisting of a fipple like a recorder's and a tube with a piston in it. Thus it has an air reed like some woodwinds, but varies the pitch with a slide. The construction is rather like a bicycle pump. Because the air column is cylindrical and open at one end and closed at the other, it overblows the third harmonic.