Organ pipes are musical instruments which are used to produce musical sound by blowing air into the pipe. Organ pipes are two types (a) closed organ pipes, closed at one end (b) open organ pipe, open at both ends.

Why are organ pipes closed at one end?

An organ pipe closed at one end can allow standing waves which have a node (zero displacement) at that end and an antinode (maximum displacement) at the other (neglecting a small 'end correction'). This is called the 'fundamental'.

What instruments are closed pipe?

Clarinets and saxophones are examples of closed pipe instruments, which produce resonance when there is a node at the closed end (although it isn't completely closed because of the mouthpiece, sound waves still reflect as if it is) and an antinode at the open end.