The human male genitalia.
What's long hard and can transmit diseases? A rusty pipe!
A strong rich singing voice has pipes. The anatomical equipment needed to have a good, strong singing voice that matches pitches and has a good sense of singing style.
Aretha Franklin....that woman's got pipes.
“ Now I get that feeling
Something ain't right
I look to my right
And I'm like, damn
There go that flexin' nigga
He wavin' his pipe” - King Von, Crazy Story pt. 3