The document discusses different types of flutes including bird whistles, nose flutes, and alto/bass flutes. Bird whistles are small instruments that can mimic bird sounds when filled with water. Nose flutes are played through the nose in parts of Polynesia, Africa, China, and India. The alto flute is a lower pitched western concert flute that is sometimes called a bass flute, which can be confusing as the bass flute is a distinct instrument.