Powerhouse is a 1937 instrumental composition by jazz bandleader Raymond Scott. It is perhaps best known today as the iconic "assembly line" music in animated cartoons released by Warner Brothers in the 1940s, 1950s, and early 1960s.
History of title
Scott's Quintette (actually a sextet) first recorded "Powerhouse" in New York on February 20, 1937, along with three other titles. This recording was first commercially issued on the Irving Mills-owned Master Records label as Master 111 (mx. M-120-1), coupled with another Scott composition, "The Toy Trumpet."
After the demise of the Master label late in 1937, "Powerhouse" was reissued on Brunswick 7993, and subsequently on Columbia 36311 (after the CBS purchase of ARC, which included the Brunswick catalog). The same take was issued on all releases. (An unreleased 1939 recording by the original Scott Quintette was issued in 2002 on the 2-CD Scott compilation Microphone Music, on the Basta label.)
Both "Powerhouse" and "The Toy Trumpet" remained in Scott's repertoire for decades, both were adapted for Warner cartoon soundtracks by music director Carl Stalling along with a dozen other Scott titles, and both have been recorded by numerous other artists. Stalling, who spiced his scores with "Powerhouse" dozens of times, never created a complete version of the work; all his adaptations exist as excerpts.
Structure of composition
Structurally, "Powerhouse" consists of two distinct—and seemingly unrelated—musical themes, played at different tempos. Both have been used in numerous cartoons. After an extended introduction and vamp introducing each member of the quintet in turn (in pyramid fashion enlarging the texture), the first theme, sometimes referred to as "Powerhouse A," commences in a frantic four-bar 16th-note passage, outlining a tonic sixth harmony in the key of E-flat (C – E♭– G♭– B♭), with chromatic lower-neighbor decoration, typically employed in chase and high-speed vehicle scenes to imply whirlwind velocity. This running motif is modally ambiguous in terms of major or minor, and this is emphasized in the accomanying bass line. After an eight-bar bridge in falling 16ths heard originally from the tenor sax, the theme repeats, concluding with a 2-bar variant of this motif in syncopated staccato eighths. A twenty-bar interlude provides mild relief from the hubbub, the last eight bars of which are notable for their impressionistic chromaticism. The frenetic 16ths return for a quick 16-bar chorus. A brief moment of silence then occurs, commonly referred to as a caesura.
The slower theme, at not quite half the tempo of “A”, referred to as "Powerhouse B," is the "assembly line" music, which sometimes accompanies scenes of repetitive, machine-like activity. It begins (after the drums start the tattoo in the new tempo) with a 2-bar ostinato bass setting up the seeming relative minor (C – E – E♭– G♭ – F – D – E♭ – E). The clarinet and sax then present the iconic “B” motif, which alternates the use of E-natural and E-flat in a repeating pattern, to reassert the modal ambiguity (is the powerhouse AC or DC?). This is followed up by a truncated (14-bar) double chorus in F for the solo tenor sax. Once again, a brief full stop.
A repeat of the A section, with a slightly shortened vamp, ensues, with a seven-bar coda (in place of the interlude) to wrap things up. "Powerhouse" in its entirety places "B" in the center while "A" opens and closes the work, in the sequence A-B-A (Ternary form).
Acquisition of Scott catalog by Warner Bros.
In 1943, Scott's music publishing company, Circle Music, was sold to Warner Brothers. Because Scott's titles were now controlled by Warner, Stalling was given access to the composer's catalog to adapt his popular melodies in Warner cartoon scores. Research has not yet determined whether the acquisition of Scott's catalog and subsequent adaptions by Stalling were intentional or serendipitous. Many of Scott's late 1930s compositions had an animated, frenetic quality, and his titles were humorous and absurd (e.g., "Boy Scout in Switzerland," "War Dance for Wooden Indians," "Reckless Night on Board an Ocean Liner," and "Dinner Music for a Pack of Hungry Cannibals," all of which were quoted by Stalling in various cartoons). 
There is a prevalent misconception that Scott composed music for Warner cartoons. However, the Scott titles adapted by Carl Stalling were originally composed between 1936 and 1942 for Scott's small jazz ensemble (his "Quintette") or his expanded big band. Scott had no involvement with Stalling's usages, he never worked for Warner Bros., and except for a one-minute TV commercial for County Fair Bread in the 1960s, he never composed music for animation.
Use in WB Cartoons
The first use of "Powerhouse" in a cartoon occurred in the 1943 Looney Tunes short Porky Pig's Feat, directed by Frank Tashlin. Also in 1943, it was used in the Private Snafu shorts Gripes, Spies, and Rumors. It was subsequently featured in over 40 other Warner cartoons. The best-known "assembly-line" usage of "Powerhouse B" occurs in Bob Clampett's Baby Bottleneck (1946), in which newborn babies (of various species) are processed on a conveyor belt in time to the melody.
The "Powerhouse A" section featured prominently during Bugs Bunny's altercation with a gremlin in Clampett's 1943 Merrie Melodies cartoon Falling Hare. The 1953 Merrie Melodies cartoon Duck Dodgers in the 24½th Century, directed by Chuck Jones, contains Stalling's lengthiest adaptation of the "Powerhouse A" section, clocking in at one minute and twenty-five seconds.
Other Warner cartoons which contain quotes from "Powerhouse" include Birdy and the Beast (1944), Cat-Tails for Two (1953), Early to Bet (1951), Falling Hare (1943), His Bitter Half (1950), House-Hunting Mice (1948), It's Hummer Time (1950), Jumpin' Jupiter (1955), Rocket Squad (1956), Sheep in the Deep (1962), Compressed Hare (1961), and dozens more.
An entire 1993 episode of Animaniacs, "Toy Shop Terror," was set to Warner Bros. music director Richard Stone's arrangement of the composition. It can also be heard as a systematic rock theme in the 2003 feature film Looney Tunes: Back in Action.
Use in Other Cartoons
The original Raymond Scott Quintette recordings, including "Powerhouse," were licensed in the early 1990s for soundtrack usage in twelve episodes of The Ren and Stimpy Show. Various passages of the tune have been arranged for use in The Simpsons, Duckman, The Bernie Mac Show, and The Drew Carey Show (in a brief scene involving an animated character). "Powerhouse" also served as bumper theme music for the Cartoon Network from 1997 to 2002.
"Powerhouse" has been used In The Simpsons four times. The first occurs in ""And Maggie Makes Three" (Season 6, Episode 13) during a scene at a bowling alley. In the episode "Bart Has Two Mommies" (Season 17, Episode 14), "Powerhouse" B is adapted in a scene that pays homage to the 1937 Disney short, The Old Mill, when Homer Simpson gets caught in the Old Mill while trying to save his Rubber Duckie. In the episode "Little Big Girl" (Season 18, Episode 12), "Powerhouse" was used during the sequence where the fire at Cletus' farm is lit. In the episode "The Fool Monty" (Season 22, Episode 6), "Powerhouse" was adapted as background music for a construction scene in which Charles Montgomery Burns, having lost his memory, is led to a dangerous construction site by Homer Simpson, who is seeks revenge for Burns' years of cruel behavior. Burns walks along moving girders, narrowly avoids flying rivets, and other well-worn cartoon construction site gags. Simpsons creator Matt Groening once ranked "Powerhouse" as #14 on a list of his "100 Favorite Things."