Musical sewers - Fact or Fiction?

[Phrontist]

From BLDGBLOG

**Unreliable sources suggest that the earliest Victorian sewer engineers were also trained to make musical instruments: thus many storm drains beneath London are designed like saxophones, tubas, and flutes. Distant changes in air pressure cause the whole system to shudder, whistling subliminally on the edges of the wind, a soundtrack for the city so beautiful it’s often hypnotic. **If you wait long enough in certain alleys in Soho, you’ll hear it, droning beneath the rustle of crisp bags and trash.
It is rumored that the final, dying words of composer John Cage were: “Make sure they play my London piece… You have to hear my London piece…” He was referring, many now believe, to a piece written for the subterranean saxophony of London’s sewers.

The bolded part is what I’m interested in. Can anyone find any more “reliable” sources? Verify if this is true or false? Feasible? First-person accounts?

[GorillaMan]

The very first sentence had my wtf-antennae erect:

“Rumor has it that a university outside Manchester”…you mean Liverpool? Or maybe just Salford? If they can’t even identify the location other than ‘not somewhere’, then the urban myth surely dies.

[Chronos]

Sewer systems are huge compared to any musical instrument. To get an audible tone out of a pipe miles long, you’d need such a high harmonic that you’d have essentially no tone control, so there’d be no way you could get anything resembling “music” out of such a pipe. You might get something interesting if you recorded the pressure variations and then shifted them up a dozen octaves or so, but you couldn’t even use a regular microphone for the recording.

[Meurglys]

Well, this isn’t really connected, but there used to be a road in France that played a tune when you drove over it…

Euphonic Roadsurface