Alessi Sapper Kettle  

Can't see your picture...
...but that's ok.
Your kettle should have a spring that holds the spout tightly closed. If that spring is broken, steam can escape before it passes through the whistle.
No idea what's clogging your whistle's pitch pipe, but replacements (along with replacement springs) are available from Alessi and Alessi dealers. Unicahome, for example, sells the pitch pipes for $17 and the spring for $3.
http://www.unicahome.com/p95/alessi/sapper-whistling-kettle-by-richard-s...

I got one note
Yes, I think you are right, as far as the spring goes. It's not providing any torque at all. I tried boiling water again, and now I get a note out of the shorter pipe. I tried covering the working pipe while the pot boiled to see if I could force some steam out of the clogged one, but no luck. I don't want to push it, for fear of scalding my face! It might be worth buying a few parts, if I could remove the spout. That's another problem.
Thank you for your suggestions.

A night ...
in vinegar will take all the calcium away!!...
Normally a spring like that does not loose it's strength easily. It might might have been disassembled in the past and not been mounted properly.

Whistling tea kettles annoy me...
so I use an electric Hobbs that turns itself off.
What would be really great, though entirely science fiction I suppose, would be tea kettle that uses its steam to pressurize a thruster (or series of thrusters) that raises the kettle off the burner a quarter inch and causes it to slide off the burner on to a tile beside the burner. Now that would be a great stove top kettle. 🙂
For that I might retire my Hobbs.

They must have annoyed Richard Sapper, too...
...which is why his kettle whistles a pleasant perfect fourth: B and E.
Another Alessi kettle, Frank Gehry's "Pito", addresses the problem by whistling a couple octaves below the pitch of most kettles. It's a little odd the first time you hear it -- takes a while to realize that it's the teakettle making that low tone -- but it's much nicer than the insistent shriek that comes out of the others.

I do love a product
that has easily available replacement parts.
(i also would try a good soaking in vinegar)

After nearly a year
of daily use, i'm very happy with my
Chantal pro design...
(odd that it seems to be out of stock when i just
looked it up on a few retail sites!)

Rockland...that's MY kettle too!
It's much bigger than it looks and mine works perfectly.
I have a fairly large house and I need to hear when the kettle has come to a boil, hence my need for a whisler. Some people don't like 'em, and I understand.
It is strange that Chantal discontinued the kettle, tho.

Vinegar, Yes
I soaked the pipes in vinegar all night and got a whole lot of junk out of there. And I actually did get a sound out of the other pipe, but now it's not working again. Sad! It sounded so cool with both notes--like a Swiss train arriving.
Maybe I do need to invest in new reeds, but how to remove and reinstall. Think I'll go to a store where they sell the new one and see if they have any instructions.
Thank you all.

Link for 20 designer kettles
Gehry's is really strange. Can't tell how it would work. At least it is not deformative, like so much of his architecture recently.
http://ifitshipitshere.blogspot.com/2008/12/stainless-steel-tea-kettles-...

Vinegar works for so many things...
It works especially well for cleaning the augur and filter in an old fashioned, hand cranked meat processor, too.

DC...
I can see why you're mystified; the operation is trivially simple, but it really isn't clear from that photograph.
One of the two mahogany fish on Gehry's Pito kettle (the one on the right in your photo) is the handle. It's firmly mounted to the kettle and doesn't move.
The other fish is the whistle. Your photo shows it in the spout, where it lives most of the time; it's completely removed from the kettle for filling and pouring.
[edited to add photo of kettle with whistle removed]

Great kettle Barry.
The Honer harmonic is loud! But has a nice beginning pitch.
I need the large capacity with a Chemex ritual every morning.
The quality is not matched by any that i researched.
If i needed an occasional cup of tea, i may have chosen another.

Rockland, one of the things
I like best about the Chantal teakettle is its design...traditional in it's location of handle and spout, but sculpturial.
Seems to me that some of those kettles shows above are too fussy for my taste, and it's essential for the spout to be located on the top and the kettle must be an easy pour.
I had considered the Alessi Michael Graves teakettle, but I wasn't too keen on a polish chrome-like steel finish (shows too many marks) and I didn't want a removable whistling mechanism. The Chantal opens easily.
However, some people have had problems with the mechanism that holds the Chantal whistling cover in place...luckily, mine is holding up fine.