Rock and pop rhythms

Most rhythms in rock and blues are based on 4/4 time with a backbeat; however, many variations are possible. A backbeat is a syncopated accentuation on the "off" beat. In a simple 4/4 rhythm these are beats 2 and 4.^[2] Emphasized back beat, a feature of some African styles, defined rhythm and blues recordings in the late 1940s and so became one of the defining characteristics of rock and roll and much of contemporary popular music.

Rock and pop harmony

Harmonically, in rock music, the most common way to construct chord progressions is to play major and minor "triads", each comprising a root, third and fifth note of a given scale. An example of a major triad is C major, which contains the notes C, E and G. An example of a minor triad is the A minor chord, which includes the notes A, C and E. Interspersed are some four-note chords, which include the root, third and fifth, as well as a sixth, seventh or ninth note of the scale. The most common chord with four different notes is the dominant seventh chord, which include a root, a major third above the root, a perfect fifth above the root and a flattened seventh. In the key of C major, the dominant seventh chord is a G7, which consists of the notes G, B, D and F.

Three-chord progressions are common in earlier pop and rock, using various combinations of the I, IV and V chords, with the twelve-bar blues particularly common. A four chord progression popular in the 1950s is I-vi-ii-V, which in the key of C major is the chords C major, a minor, d minor and G7. Minor and modal chord progressions such as I-bVII-bVI (in the key of E, the chords E major, D major, C major) feature in popular music.

A power chord in E for guitar. This contains the notes E, B (a fifth above) and an E an octave higher.

In heavy metal music, rhythm guitarists often play power chords, which feature a root note and a fifth above, or with an octave doubling the root. There actually is no third of the chord. Power chords are usually played with distortion.

Arpeggios

One departure from the basic strummed chord technique is to play arpeggios, i.e. to play individual notes in a chord separately. If this is done rapidly enough, listeners will tend to hear the sequence as harmony rather than melody. Arpeggiation is often used in folk, country, and heavy metal, sometimes in imitation of older banjo techniques. It is also prominent in 1960s pop, such as The Animals' "House of the Rising Sun", and jangle pop from the 1980s onwards. Rhythm guitarists who use arpeggios often favor semi-acoustic guitars and twelve string guitars to get a bright, undistorted "jangly" sound.

The Soukous band TPOK Jazz additionally featured the unique role of mi-solo, (meaning "half solo") guitarist, playing arpeggio patterns and filling a role "between" the lead and rhythm guitars.^[3]

Riffs

In some cases, the chord progression is implied with a simplified sequence of two or three notes, sometimes called a "riff". That sequence is repeated throughout the composition. In heavy metal music, this is typically expanded to more complex sequences comprising a combination of chords, single notes and palm muting. The rhythm guitar parts in compositions performed by more technically oriented bands often include riffs employing complex lead guitar techniques. In some genres, especially metal, the audio signal from the rhythm guitar's output is often subsequently run through some form of effect pedal or overdriven guitar amplifier in order to create a thicker, crunchier sound for the palm-muted rhythms.

Interaction with other guitarists

In bands with two or more guitarists, the guitarists may exchange or even duplicate roles for various songs or several sections within a song. In those with a single guitarist, the guitarist may play lead and rhythm at numerous times or simultaneously, by overlaying the rhythm sequence with a lead line.

Crossover with keyboards

Electronic effects units such as delay pedals and reverb units enable electric guitarists to play arpeggios and take over some of the role of a synthesizer player in performing sustained "pads". These can serve as sonic backgrounds in modern pop. Creating a pad sound differs from usual rhythm guitar roles in that it is not rhythmic. Some bands have a synthesizer performer play pads. In bands without a synth player, a guitarist can take over this role.

Replacing lead guitar

Some rhythm techniques cross over into lead guitar playing. In guitar-bass-and-drums power trios guitarists must double up between rhythm and lead. For instance Jimi Hendrix combined full chords with solo licks, double stops and arpeggios. In recent years, "looping pedals" have been used to supply chord sequences or riffs over which musicians can then play the lead line, simulating the sound achieved by having two guitarists.

Equipment

A rhythm guitarist usually aims to generate a strong rhythmic and chordal sound, in contrast to the lead guitarist's goal of producing sustained, often higher-pitched melody lines, that listeners can distinguish above the other instruments. As a result, rhythm and lead players often use different guitars and amplifiers. Rhythm guitarists may employ an electric acoustic guitar or a humbucker-equipped electric guitar for a richer and fatter output. Also, rhythm guitarists may use strings of a larger gauge than those used by lead guitarists. However, while these may be practices, they are not necessarily the rule and are subject to the style of the song and the preference of the individual guitarist.

While rhythm guitarists in metal bands use distortion effects, they tend to use less of the modulation effects such as flangers used by lead guitar players. Whereas the lead guitarist in a metal band is trying to make the solo tone more prominent, and thus uses a range of colorful effects, the rhythm guitarist is typically trying to provide a thick, solid supporting sound that blends in with the overall sound of the group. In alternative rock and post-punk, however, where the band may be aiming to create an ambient soundscape rather than an aggressive Motörhead-style "Wall of Sound", the rhythm guitarist may use flanging and delay effects to create a shimmering background, or (as in The Smiths song "How Soon Is Now?"), a reverberating tremolo effect.

Jazz harmony

Jazz guitarists use their knowledge of harmony and jazz theory to create jazz chord "voicings", which emphasize the 3rd and 7th notes of the chord. Unlike pop and rock guitarists, who typically include the root of a chord (even, with many open chords and barre chords, doubling the root), jazz guitarists typically omit the root. Some more sophisticated chord voicings also include the 9th, 11th, and 13th notes of the chord. A typical jazz voicing for the chord G7 would be the individual notes B, E, F, and A. This voicing uses the 3rd (the note B), the 7th (the note F), along with the 6th (the note E) and the 9th (the note A).

In some modern jazz styles, dominant 7th chords in a tune may contain altered 9ths (either flattened by a semitone, which is called a "flat 9th", or sharpened by a semitone, which is called a "sharp 9th"); 11ths (sharpened by a semitone, which is called a "sharp 11th"); 13ths (typically flattened by a semitone, which is called a "flat 13th").

Jazz guitarists need to learn about a range of different chords, including major 7th, major 6th, minor 7th, minor/major 7th, dominant 7th, diminished, half-diminished, and augmented chords. As well, they need to learn about chord transformations (e.g., altered chords, such as "alt dominant chords" described above), chord substitutions, and re-harmonization techniques. Some jazz guitarists use their knowledge of jazz scales and chords to provide a walking bass-style accompaniment.

Jazz guitarists learn to perform these chords over the range of different chord progressions used in jazz, such as the II-V-I progression, the jazz-style blues progression, the minor jazz-style blues form, the "rhythm changes" progression, and the variety of chord progressions used in jazz ballads, and jazz standards. Guitarists may also learn to use the chord types, strumming styles, and effects pedals (e.g., chorus effect or fuzzbox) used in 1970s-era jazz-Latin, jazz-funk, and jazz-rock fusion music.

Big band rhythm

In jazz big bands, popular during the 1930s and 1940s, the guitarist is considered an integral part of the rhythm section (guitar, drums and bass). They usually played a regular four chords to the bar, although an amount of harmonic improvisation is possible. Freddie Green, guitarist in the Count Basie orchestra, was a noted exponent of this style. The harmonies are often minimal; for instance, the root note is often omitted on the assumption that it will be supplied by the bassist.

Small group comping

When jazz guitarists play chords underneath a song's melody or another musician's solo improvisations, it is called comping, short for accompanying. The accompanying style in most jazz styles differs from the way chordal instruments accompany in many popular styles of music. In many popular styles of music, such as rock and pop, the rhythm guitarist usually performs the chords in rhythmic fashion which sets out the beat or groove of a tune. In contrast, in many modern jazz styles within smaller, the guitarist plays much more sparsely, intermingling periodic chords and delicate voicings into pauses in the melody or solo, and using periods of silence. Jazz guitarists commonly use a wide variety of inversions when comping, rather than only using standard voicings.^[4]

Gypsy pumping

La Pompe.^[5] Play^ⓘ

Gypsy jazz is acoustic music, usually played without a drummer. Rhythm guitar in gypsy jazz uses a special form of strumming known as "la pompe", i.e. "the pump". This form of percussive rhythm is similar to the "boom-chick" in bluegrass styles; it is what gives the music its fast swinging feeling. The strumming hand, which never touches the top of the guitar, must make a quick up-down strum followed by a down strum. The up-down part of la pompe must be done extremely fast, regardless of the tempo of the music. It is very similar to a grace note in classical music, albeit the fact that an entire chord is used. This pattern is usually played in unison by two or more guitarists in the rhythm section.

Jazz chord soloing

Jazz guitar soloists are not limited to playing single notes by their instrument. This allows them to create "chord solos" by adding the song's melody on top of the chord voicings. Wes Montgomery was noted for playing successive choruses in single notes, octaves and finally a chord solo. This technique differs from chord-melody soloing in that it is not intended to be used unaccompanied