Digitech Whammy IV
Price Paid at Sam Ash: $200

The Digitech Whammy is a pitch-shifter effects pedal manufactured by Digitech. It gives musicians the ability to shift the pitch of their electric guitar up or down in real time by rocking a treadle pedal up and down with their foot, similar to how a wah pedal affects the tone of a guitar based on the position of the treadle.

The WH-1 Whammy pedal, the original whammy, first manufactured in 1991, remains the most sought-after. Tom Morello was the first guitarist to make liberal use of the Whammy pedal's possibilities and it has become his trademark sound, appearing on nearly every song on Rage Against the Machine's debut album.

Controls
It is controlled by a rocker and a single rotary knob, from which 16 different presets could be selected; five "Whammy" effects, nine "Harmony" effects, and two "Detune" effects.

Harmony effects
Second up - third up
Minor third up - third up
Third up - fourth up
Fourth up - fifth up
Fifth up - sixth up
Fifth up - seventh up
Fourth down - third down
Fifth down - Fourth down
One octave down - one octave up

Detune effects
Shallow
Deep

Whammy effects
One octave up
Two octaves up
Two semi-tones down
One octave down
Two octaves down
Dive bomb - three octaves down
Drop tune - two semi-tones down

Notable users
A popular misconception is that American musician Jack White, and English musician Matt Bellamy use the WH-1 Whammy; in reality, both use the Whammy 4. Notable musicians who have used the WH-1 Whammy include:

Tom Morello of Rage Against the Machine and Audioslave (used on virtually every album from RATM and Audioslave)
Jonny Greenwood of Radiohead (can be heard on "Just", "My Iron Lung", and "Subterranean Homesick Alien")
Jack White of the White Stripes and the Raconteurs
Kevin Shields of My Bloody Valentine
Dimebag Darrell of Pantera
Kirk Hammett of Metallica
Steve Vai
Eddie Van Halen
Scott Ian of Anthrax
Joe Satriani
David Gilmour (first used on "Marooned" and "Wearing the Inside Out" from Pink Floyd's The Division Bell, also used on "The Blue" from his solo album, On an Island)
Tak Matsumoto of B'z
David Bryant of Godspeed You! Black Emporer
The Edge of U2 (can be heard in the beginning of "Even Better Than the Real Thing" and the chorus and ending of "Gone")
Nels Cline
Matthew Bellamy of Muse
T.M.Stevens
Vernon Reid of Living Colour
Doug Wimbish of Living Colour
Herman Li and Sam Totman of Dragonforce
Adam Franklin of Swervedriver
John Frusciante of the Red Hot Chili Peppers
Agata of Melt Banana
Aaron Colbourne of 83 Floating Cubes
Larry LaLonde of Primus
Toni Wirtanen of Apulanta
Richard Z. Kruspe of Rammstein (can be heard in in "Stein um Stein")
Daniel Johns of Silverchair