E.g. flute maker putting lips to metal pipe (5-6)

'pipe' is the definition.
Both the definition and answer are singular nouns.
Perhaps they are linked in a way I don't understand?

'e g flute maker putting lips to metal' is the wordplay.
I cannot really see how this works, but
'e' is found in the answer.
'g' is found in the answer.
'metal' could be 'sb' (Sb is an example) and 'sb' is found within the answer.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?