Instrumental rock is a type of rock and roll music which emphasises musical instruments, and which features little or no singing.
Examples of instrumental rock music can be found in practically every subgenre of rock, often from musicians who specialise in the style, like Dick Dale, The Ventures, Joe Satriani and Steve Vai.
While many rock bands perform occasional instrumental pieces, those whose music predominantly features vocals are not typically classified as instrumental rock.
Instrumental rock was most popular during rock and roll's first decade (mid-1950's to mid-1960s), before the British Invasion.
One notable early instrumental was "Honky Tonk" by the Bill Doggett Combo, with its slinky beat and sinuous saxophone-organ lead. And bluesman Jimmy Reed charted with "Boogie in the Dark" and "Roll and Rhumba".
Jazz saxophonist Earl Bostic revived his career with instrumentals like "Harlem Nocturne" and "Earl's Rhumboogie". (Other jazz musicians who scored pop hits include Tab Smith and Arnett Cobb). Several rhythm and blues sax players had hit instrumental songs, including Big Jay MacNeeley, Red Prysock, and Lee Allen, whose "Walking with Mr. Lee" was quite popular.
There were several notable blues instrumental songs during the 1950s; Little Walter's rollicking "Juke" was a major hit.
Instrumental hit songs could emphasize electronic organ (The Tornados' "Telstar", Dave "Baby" Cortez's "The Happy Organ") or the saxophone (The Champs' "Tequila"), but the guitar was most prominent.Duane Eddy scored several hits (his best known probably being "Rebel 'Rouser") and Link Wray's ominous "Rumble" might be only instrumental rock hit ever banned from some radio stations.
The Ventures' precise guitar work was a major influence on many later rock guitarists; they also helped shape surf music, which at this stage consisted almost entirely of heavily reverbed guitar instrumentals.
Surf rock was quite popular in the early 1960s, and was generally rather simple and melodic--one exception being Dick Dale, who gained fame for his quick playing, often influenced by the music of the middle east, and frequently using exotic scales.
Following the British Invasion, rock changed appreciably, and instrumental hits came mostly from the R&B world. Notable artists include Booker T. & the MG's and saxophonist Junior Walker.
Steve Cropper of the MG's asserts:
"We had trouble getting airplay because disc jockeys did not like playing songs without vocals on them. It got worse and worse and worse until they finally pushed every instrumental band in the country out of business." 
Funk and disco produced several instrumental hit singles during the 1970s.
The jazz fusion of the 1970s often had considerable stylistic cross-over with rock, and groups like Return to Forever, Mahavishnu Orchestra and Weather Report had sizeable followings among rock fans. Guitarist Jeff Beck released several popular instrumental albums which straddled rock and fusion.
Progressive rock and art rock performers of the 1960s and 1970s deserve some mention. Many of these musicians featured virtuostic instrumental performances (and occasional instrumental songs), but many of their compositions also featured vocals.
During the 1980s, the instrumental rock genre was dominated by several guitar soloists.
Swedish virtuoso Yngwie Malmsteen made a name for himself in 1984 by playing in the popular band Alcatrazz, and then by releasing his debut solo album Rising Force later that year, which made it to #60 on the Billboard Charts. Joe Satriani's 1987 album Surfing With The Alien was a surprise hit, containing the ever-popular instrumental ballad "Always With Me, Always With You"—a staple for guitarists learning their craft.
After Malmsteen left Alcatrazz, he was replaced by the extravagant Steve Vai, who had previously been playing with the Frank Zappa band. Continuing the tradition (and following a brief stint in David Lee Roth's band from 1986 to 1988), Vai went on to release a number of highly acclaimed solo albums. Arguably the best-known of these was his 1990 release, Passion And Warfare, which at the time really began to push the boundaries of what could be done in instrumental rock.
Jason Becker was also considered by many to be a fantastic player, who released two albums with Cacophony. Cacophony were a primarily instrumental group featuring Becker and Marty Friedman (the latter of whom went on to play with the legendary thrash metal band Megadeth). After the release of Cacophony's second album Go Off! in 1988, Becker released two solo albums before being diagnosed with amyotrophic lateral sclerosis. Sadly, he is now confined to a wheelchair and is completely unable to play.
Recommended 1980s instrumental rock albums;
Yngwie Malmsteen — Rising Force (1984)
Tony MacAlpine — Edge Of Insanity (1986)
Vinnie Moore — Mind's Eye (1986)
Joe Satriani — Surfing With The Alien (1987)
Cacophony (Jason Becker and Marty Friedman) — Speed Metal Symphony (1987)
Steve Morse — High Tension Wires (1989)
During the 1990s, instrumental music flourished among indie-rock groups and with the popularity of so-called "post rock" groups like Tortoise, Mogwai and Cul de Sac.
Don Caballero gained notice for their music as did neo-surf-rockers The Mermen and Man... or Astro-Man?.
Quentin Tarantino's smash hit film Pulp Fiction made heavy use of rock instrumentals on its soundtrack, spurring some interest in classic instrumentals, and revitalizing Dick Dale's career.
With the rise of grunge music, guitar-orientated instrumental rock of the type popular in the 1980s became less popular, and there were few artists who continued to thrive in that style. The instrumental stars from the 1980s -- Satriani, Vai and Malmsteen, to name but a few -- were often lumped in with fading glam metal movement, whether fairly or not, and their popularity waned.
Over the past few years there have been many new releases of instrumental rock albums. The majority of the popular guitar heroes from the 1980s have made rejuvinated and generally well-received comebacks, thanks largely to the revitalized sound apparent on their recent releases. Artists such as Steve Morse, Marty Friedman, Ron Jarzombek, Joe Satriani and Malmsteen have continued releasing instrumental rock music and touring with great success. However, it is still extremely rare to hear an instrumental rock tune on the radio, or see one on the music charts.
The 2000s have seen a rise in the popularity of bands that have been labeled post-rock; many of these bands have created instrumental rock songs. Constellation Records has released some of the best-known examples of instrumental post-rock, such as Godspeed You! Black Emperor and Do Make Say Think. Mogwai and Explosions in the Sky are other examples of instrumental post-rock.
It should be noted that children's television programs often feature instrumental rock theme songs. The Mighty Morphin Power Rangers theme, entitled "Go Go Power Rangers", and performed by Aaron Waters, has its devotees, as does the theme for Dragon Ball Z.