||This article needs additional citations for verification. (January 2009)|
||This article may contain original research. (March 2013)|
A power trio is a rock and roll band format typically having a lineup of guitar, bass and drums, leaving out the rhythm guitar or keyboard that are used in other rock music to fill out the sound with chords. While one or more band members may sing, power trios usually emphasize instrumental performance and overall impact over vocals and lyrics.
The rise of the power trio in the 1960s was made possible in part by developments in amplifier technology that greatly enhanced the volume of the electric guitar and bass. The prototypical power trios were exemplified by late 1960s-era blues-rock/hard rock bands The Jimi Hendrix Experience, Cream, Grand Funk Railroad and The James Gang. Blue Cheer, in its most popular configuration as a power trio, was said to have adopted that format after seeing Jimi Hendrix perform at the Monterey Pop Festival. Well-known 1970s-era power trios include the Canadian progressive rock group Rush; the American band ZZ Top; the British heavy metal band Motörhead; The Jam; Robin Trower; and The Police.
Keyboard-oriented power trios using electronic organ (or synthesizer in the 1970s) also emerged, such as Atomic Rooster, the guitar-less incarnations of Soft Machine and The Nice, and progressive rock band Emerson, Lake & Palmer. Ben Folds Five is a piano rock power trio from the 1990s.
In Latin America in the 1980s and 1990s, power rock trio Soda Stereo revolutionized Latin rock and became one of the biggest rock bands in the history of Latin American music. Other Latin rock power trios include Divididos, Invisible, A.N.I.M.A.L., Los Prisioneros and (in their beginnings) Leusemia.
Although power trios fell out of fashion in mainstream rock during the early 1980s, the rise of post-punk and indie rock in the later 1980s and throughout the 1990s featured many trios, such as grunge band Nirvana and pop-punk bands such as Green Day and Blink-182. One of the biggest power trios of today is the British band Muse.
Power trios have at times been characterized as loud and bombastic, often embarking on long improvised jams that would highlight the virtuosity of the individual musicians. The American blues band, Hot Tuna, for example, when it chose to play electric, would often play six-hour sets when performing in the mid-1970s. Power trio music often reflects a blues or jazz influence, since these two types of music invite improvisation. Typically, instrumental performance and overall impact are emphasized over vocals and lyrics. For instance, Beck, Bogert, and Appice would generally be considered a power trio, whereas the Jeff Beck Group, (a similar lineup with Rod Stewart on vocals) would not.
As power trios have one guitar, one bass and one drummer, this arrangement usually requires the guitarist to play both rhythm and lead parts. The emphasis on guitar solos and crashing rhythm sections in the power trio contributed to the development of heavy metal, although some power trios would prefer hard rock labels.
The rise of the power trio was made possible in part by developments in amplifier and electric guitar/bass guitar technology that permit the instruments to provide more sound than before. Particularly, the advent of electric bass guitar defined the bottom end and filled in the gaps. Since the bass could also now be louder, the rest of the band could also play at higher volumes, without fear of being unable to hear the bass. This allowed a three-person band to have the same sonic impact as a large band but left far more room for improvisation and creativity, unencumbered by the need for detailed arrangements. As well, as with the organ trio, a 1960s-era soul jazz group centered around the amplified Hammond organ, a three-piece group could fill a large bar or club with a big sound for a much lower price than a large rock and roll band. A power trio, at least in its blues-rock incarnation, is also generally held to have developed out of Chicago-style blues bands such as Muddy Waters' trio.
The Pirates, when they established themselves in 1962-64 and again from 1976 onwards as a separate, power trio entity from Johnny Kidd & the Pirates, were pioneers of the technique of playing guitar solos with a thick chordal rhythm-guitar-like style, which was later popularised by Dr. Feelgood in the 1970s.
The prototypical power trios were exemplified by The Jimi Hendrix Experience, Blue Cheer, Grand Funk Railroad and Cream, who popularized the format during the 1960s. Cream has been called the "prototypical blues rock power trio".These groups laid down the framework for all other subsequent power trios: extended improvisation, hyperamplification through walls of amplifiers and cabinets, and the use of effects (such as delay, distortion, flangers, fuzz bass, wah pedals, etc.) to fill out and modify the guitar sound. The idea of the power trio became so pervasive during the late 1960s that it became a virtual rite of passage for young musicians. After the break-up of the Beatles in 1970, John Lennon released his debut solo album Plastic Ono Band in the fashion of a power trio with Lennon alternatingly on guitars and piano. Electric blues bands such as Rory Gallagher had a more "stripped-down" feeling, with no guitar effects to alter the sound, but focusing more on the energy of the performance.
The first Keyboard-oriented power trio was the Scottish band 1-2-3 (later Clouds) in 1966. Thereafter, other keyboard-oriented power trios also emerged such as Atomic Rooster, the guitar-less incarnations of Soft Machine and The Nice, and perhaps the most successful, Emerson, Lake & Palmer (formed from Atomic Rooster and The Nice keyboard trios). Another important keyboard-based trio from Argentina was Alas, perhaps the only power trio of these characteristics in Latin America. These trios centered on the sound of the electronic organ and in the 1970s, the analog synthesizer.
Experimentation in the 1970s and 1980s 
During the late 1960s, many groups used power trio instrumentation while adding a vocalist. These include Led Zeppelin, The Who, Black Sabbath, and Free. Although none of these were ever particularly identified as such, the music that they created is influenced by, and follows the same musical format as, many of the pioneering power trios. Likewise, Mountain is often erroneously referred to as a power trio, even though there were four instrumentalists (guitar, bass, drums, and keyboards) in the band. Many punk rock bands, for example the Ramones and the Sex Pistols, would follow the power trio plus vocalist model, which was also used by proto-punk band The Stooges.
Some power trios also experimented with keyboards and sequencers in the studio, most notably the Canadian trio Rush, whose bassist-frontman Geddy Lee has often demonstrated his multi-instrumental capabilities on diverse rock albums such as 1977's A Farewell to Kings and 1985's Power Windows. Modern digital technology has also enabled a power trio to duplicate their studio performances in concert, as evidenced by Rush's 1989 live album, A Show of Hands, where Lee simultaneously sings, plays bass, and plays keyboard with foot pedals. This technology, in combination with their style and production, have earned the band the nickname of "Canadian Power Trio".
Some 1970s British groups, such as Genesis and UK began with larger lineups, but eventually became keyboard-oriented trios in the mode of The Nice, and later, Emerson, Lake & Palmer. Other well-known trios from the 1970s and 1980s include The James Gang; Glass Harp; Raven; Budgie; Grand Funk Railroad; Triumph; Blue Cheer; Johnny Winter's Progressive Blues Experiment; Motörhead; The Minutemen; West, Bruce and Laing; The Jam; The Police; Rush; Zebra; ZZ Top; Robin Trower Band and, until the album Nightlife, Thin Lizzy.
A late 70s jazz fusion trio of John McLaughlin (guitar) Jaco Pastorius (bass) and Tony Williams (drums) unashamedly returned to the original concept of the power trio with their short-lived "Trio of Doom" album. (Cream and the Jimi Hendrix Experience are specifically mentioned in the album's sleeve notes.) However the experiment lasted for only one live performance and one studio session.
1980s and 1990s 
Although power trios fell out of fashion in mainstream rock during the 1980s, the rise of post-punk and indie rock in the 1980s and 1990s featured many trios. During this time the configuration experienced a renaissance of sorts with groups such as Nirvana, Silverchair, Meat Puppets, Violent Femmes, Babes in Toyland, Primus, Hüsker Dü (and spin off bands Nova Mob and Sugar), Walt Mink, the Minutemen, Dinosaur Jr, Sebadoh, Melvins, Fudge Tunnel, Galaxie 500, DC3, Nomeansno, The Presidents of the United States of America, Low, the Jon Spencer Blues Explosion, Killdozer, Cosmic Psychos, Therapy?, Placebo, Jawbreaker, Bratmobile, Sleater-Kinney, the Screaming Blue Messiahs, Gov't Mule, Morphine (bass, sax and drums) and Ben Folds Five (piano, bass and drums). After the disappearance of their guitarist Richey James Edwards, the Manic Street Preachers continued as a three-piece (although Edwards only appeared on record on one song, and was always turned down or even entirely off onstage: his only real role in the band was as lyricist). The British pop rock trio The Outfield got started in the mid-1980s and continued on through the early 1990s; it's atypical for the usual power trio style for its lighter/softer pop sound. The Cure has changed from their initial trio formation to a quartet or quintet in their career, although they have returned to that format in some occasions.
Recording engineer Steve Albini's bands Big Black, Rapeman and Shellac were all three-piece bands (though Big Black usually credited their drum machine as a member in album liner notes). Similarly, British industrial band Godflesh often utilized a drum machine and two primary members, although they did at times record and tour with a second guitarist (Paul Neville of Loop), and near the end of the band's life they began working with real drummers (Bryan Mantia and later Ted Parsons) almost exclusively. The most successful rock power trio of that time was Nirvana, who crossed over to immense mainstream success.
Some trios would overdub multiple parts when recording but perform stripped-back versions of their songs live, while others (such as the Minutemen) recorded mostly live, performing "gigs in front of a mic", as Mike Watt put it. In the post-alternative era, popular trios included Sublime, One Man Army, Alkaline Trio, Green Day, Everclear, The Tea Party, Blink-182, and Gov't Mule. Also, the configuration remained popular in "progressive rock", with groups such as Rush, King's X and Mantra Sunrise. John Paul Jones uses a variant of the power trio idea in his solo tours, combining bass and keyboards with Stick player Nick Beggs and a drummer. The 1990s edition of King Crimson toured as a "double power trio" (according to leader Robert Fripp), with two drummers, two bassists and two guitars.
The traditional power trio continues to be represented by newer groups such as Muse, Yeah Yeah Yeahs, The Subways, Biffy Clyro, Wolfmother, Radio Moscow, Cog, Kashmere Club, Back Door Slam, Russian Circles, Los Lonely Boys, The Fall of Troy, The Wombats, Johnny Foreigner, State Radio, Junkyard Choir, The Young Knives, Rose Hill Drive, Seether, The Steepwater Band, Super 400, Invasion, North Mississippi Allstars, The Joy Formidable and the John Mayer Trio.
The Multi Genre group Boris only has three members, but compensates by using a double neck instrument with one neck being a guitar and one neck being a bass. They frequently use effects such as delay and echo, and fill in space with instrumental feedback. Seedy Jeezus utilize the sound of the guitar amp pushed to its limit and a drummer using the entire kit to create a full pulsing beat while the bassist alternates between a solid bassline filled with flourishes where he can. After the breakup of Godflesh, guitarist Justin Broadrick formed Jesu, which utilizes the power trio format. Broadrick's former labelmate at Earache Records, ex-Fudge Tunnel guitarist Alex Newport, also performed as part of another power trio in the band Theory of Ruin. California-based band Qui previously operated as a duo but recently became a trio (though not strictly in the power trio sense) by adding vocalist David Yow to their lineup. Adrian Belew has also recently embraced the power trio configurations for his live tours. Some power trios add to the fullness of their sound by using bass pedalboards, which are keyboards played by the feet. New York City sludge metal band Unearthly Trance also utilizes the power trio format.
- See Portrait of Vale Hamanaka/V. Vale, original keyboardist for Blue Cheer and who, along with two other members, was dropped when the band adopted the power trio format.
- Hoffman, Frank (2004). Encyclopedia of Recorded Sound, Volume 1 (2 ed.). CRC Press. p. 248. ISBN 9780203484272.
- The Encyclopaedia of Popular Music (Muze publications); also AllMusicGuide - Clouds by Bruce Eder