A fictional advertising jingle from the science-fiction novel The Demolished Man by Alfred Bester. It's a short (8-line) nonsense ditty, originally intended as the theme song for a tv-series about a crazy mathematician. In making it, every psychological trick known to the advertisement industry was put to use: the melody was "the quintessence of every melodic cliché Reich had ever heard. No matter what melody you tried to remember, it invariably led down the path of familiarity to 'Tenser, Said The Tensor'". Its very stickiness backfired, however, as people got so annoyed it had to be withdrawn at great cost.

The protagonist of the novel, Reich, uses this song to evade the ubiquitous police-employed telepaths when he carries out the first murder for centuries. With the song spinning in his head, a brief scan will not pick up his murderous intent.

Eight, sir; seven sir;
Six, sir; five, sir;
Four, sir; three, sir;
Two, sir; one!
Tenser, said the Tensor.
Tenser, said the Tensor.
Tension, apprehension,
And dissension have begun.

Note that the punch-line is a recurring quote on the Welcome to Everything-page!

In the novel, this type of song is known in the advertisement industry as a "pepsi", for reasons lost in the mist of time ("they say because the first one was written centuries ago by a character named Pepsi"). It might be rather obscure to a modern reader also, but (as teleny points out to me) this is a reference to the advertising jingle Pepsi-cola Hits the Spot from the early 1940s. This was one of the first radio jingles ever and got immensely popular, being translated into 55 languages, selling more than a million records, and was still popular a decade later when Bester wrote his novel. The lyrics go:

Pepsi-Cola hits the spot
12 full ounces, that's a lot
Twice as much for a nickel too
Pepsi-Cola is the Drink for you!
Nickel, nickel, nickel, nickle
Trickle, trickle, trickle, trickle...

JudyT says: There's now a linguistics (and science fiction) blog by this name: http://tenser.typepad.com/tenser_said_the_tensor/