pipe vs melody pipe

pipe and melody pipe both are nouns.

Word	Noun	Adjective	Verb	Adverb
pipe	Yes	No	Yes	No
melody pipe	Yes	No	No	No

As nouns, melody pipe is a hyponym of pipe; that is, melody pipe is a word with a more specific, narrower meaning than pipe:

pipe (noun)	melody pipe (noun)
a long tube made of metal or plastic that is used to carry water or oil or gas etc.	reed pipe with finger holes on which the melody is played
a tube with a small bowl at one end; used for smoking tobacco
the flues and stops on a pipe organ
a tubular wind instrument
a hollow cylindrical shape