Rock

Rock and roll (or just rock) quickly became the dominant style of music in the late 20th century. This page lists many of its aspects.

Arrangements

A large part of the rock style emerges from its arrangements. Generally, rock features a drummer, a bass player, a guitarist, and a vocalist. Many artists incorporate far more instruments, often to pull-in influence from other styles. For example, some artists will use string sections in ballads, world percussion for a primitive or latin feel, or samplers/synths for an electronica feel.

The guitar is frequently distorted, allowing it to cover a wider range of frequencies at the expense of note clarity. This also reduces the guitar's dynamic range.

Usually dynamics are eschewed altogether, using compression on the vocals, guitars, and bass to provide a consistent "loudness" to the music. The drums are used to emphasize accents and can also perform occasional build-ups by using dynamics; however, they often use different parts of the kit for accents rather than simply altered dynamics.

Drums are used much differently in rock than classical music. Rather than being used exclusively for dynamic build-ups or strong accents, the drums play on almost every beat. They serve as a time-keeper, sometimes doing so directly by riding the hi-hat or ride cymbals; other times through a repetitive pattern or groove. The bass drum, snare, and crash cymbal are often used for accents, while the toms, hi-hat, and ride cymbal are used to keep time or embellish a groove. Usually the bass drum is used on the down beat, while the snare emphasizes the back beat.

Vocals are usually contained within a single octave or even smaller range of notes, with a focus on simple melodies that most people can easily sing. A wide timbre of vocal style is emphasized, with some styles featuring screaming, processor-based distortion, or even pitchless singing (rap, spoken word, death growls).

Harmony

Rock tends to avoid strong cadences (V - I) and complex harmonies (long progressions, 4+ note chords). Dominant 7th chords are somewhat rare, but are the most common 4+ note chord seen. Suspended chords actually appear somewhat frequently; however, they are usually used in and of themselves (as a form of quartal harmony) rather than as a means to prolong a harmonic resolution. Augmented and diminished chords almost never appear, although diminished 5th intervals are common in the more extreme heavy metal sub-genres.

Rather than use complex progressions, Rock typically focuses on riff-based grooves or shuffles (that have a static harmonic fingerprint) or repeating 3 or 4 chord progressions. Often one of the chords will be non-diatonic to make the progression more interesting.

Riffs

Rock guitar playing often employs riffs instead of chords. A riff is a repeating phrase, composed mostly of single notes or simple intervals. A riff may imply a tonality or a harmony given the notes it uses as well as the sequence and relative accenting of the notes.

Example riff, establishing an E blues tonality:

E-|-------------------------|
B-|-------------------------|
G-|.-----------------------.|
D-|.-----------------------.|
A-|-2-------7p5-7p5---------|
E-|-0---------------6-5-3---|

Movement in Parallel Fifths

In classical composition, voice leading avoided moving two voices in parallel 5ths, which could feel more melodic as though the pitches were more important than the harmonies. Rock embraces parallel fifths. It tends to use simpler harmonies and less voices in general. Thus it uses movement in parallel fifths to emphasize harmonic changes.

Power Chords

Rock tends to use distorted guitar, which introduces lots of overtones above the fundamental pitch along the harmonic series, which adds in an ascending order octave, 5th, octave, major 3rd, 5th, minor 7th, and more. This means complex chords can sound quite noisy and dissonant, as not only will the fundamentals have some dissonance but also all their overtones. Even a simple minor chord can sound a bit too much for some people. Rock tends to use power chords instead.

Power chords aren't actually chords - they consist only of root and 5th; they are intervals. Typically, power chords are voiced root - 5th or root - 5th - octave. Sometimes they are voiced as simple 5th - root inversions (P4 intervals), which can make it easier to play several in quick succession. Rarely, you will see them as the 4-string root - 5th - octave - 5th.

G---------7-----12--
D------5--5--5--12--
A---5--5--5--5--10--
E---3--3--3-----10--

2 Str

3 Str

4 Str
(2 Oct)

Inv.

Inv.
4 Str

  |-|-|-|
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  |-|-|-|
5 |-|-|p|
R |i|-|-|

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  |-|-|-|
R |-|-|p|
5 |-|-|r|
R |i|-|-|

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5 |-|-|-|-|p|
R |-|-|r|-|-|
5 |-|-|m|-|-|
R |i|-|-|-|-|

  |-|
  |-|
  |-|
R |*|
5 |*|
  |-|

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  |-|-|-|
R |-|-|p|
5 |-|-|r|
R |i|-|-|
5 |i|-|-|

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5 |-|-|-|p|
R |i|-|-|-|
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  |-|-|-|-|
R |-|-|-|p|
5 |-|-|r|-|
R |i|-|-|-|
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Here's the common fingerings for these chords. *'s are used for the 2-string inversion, because any finger can be used, as well as combinations of any two adjacent fingers.

Pentatonic Scales

Rock often uses a major or minor pentatonic or 5-note scale, which is a variation of the classical 7-note major or minor scale. This is used for melodic reasons, not harmonic. Rock music tends to use traditional diatonic harmony from the full major or minor scales, including chords that contain notes not found in the pentatonic variation.

The major pentatonic scale simply drops the 4th and 7th from the major scale. The C Major Pentatonic Scale is thus, C - D - E - G - A - C. This drops all half-steps from the scale, including the leading tone.

E--------------------------------8--10--
B--------------------------8--10--------
G--------------------7--9---------------
D--------------7--10--------------------
A--------7--10--------------------------
E--8--10--------------------------------
   C  D  E  G  A  C  D  E  G  A  C  D

The minor pentatonic scale drops the 2nd and 6th from the minor scale. The A Minor Pentatonic Scale is thus, A - C - D - E - G - A. Again, this drops all half-steps from the scale.

E--------------------------------5--8--
B--------------------------5--8--------
G--------------------5--7--------------
D--------------5--7--------------------
A--------5--7--------------------------
E--5--8--------------------------------
   A  C  D  E  G  A  C  D  E  G  A  C

Notice, like the C Major and A Minor, C Major Pentatonic and A Minor Pentatonic consist of the same notes - they are relatives.

These pentatonic scales avoid the tension associated with the leading tone as well as the other half-step normally found in the major/minor scales; yet they clearly have their own tonality which emphasizes the tonic note. The decreased tension follows the general theme in rock which is to avoid strong cadences or resolutions in favor of keeping a musical flow.

C

A

G

E

D

Major

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|-|x|-|o|
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|o|-|-|x|
|o|-|-|o|

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Minor

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Note: there are more pentatonic scales than the two listed above. These are simply the most common for rock music. See Exotic Scales.

Song Structure

Rock songs are typically quite simple, some containing no more than two sections of verse and chorus. Some even use the same harmonic progression for the chorus as the verse. Most do not use modulation, keeping the song in the same tonality, although it might not fit perfectly neatly into a major or minor key. Sometimes, a brief pre-chorus section is used between verse and chorus.

The verse is typically more calm than the chorus section, used to establish the tonality, a lyrical theme, and a general mood. It usually does not create musical tension in the harmonic sense but may present a lyrical idea that requires elaboration or resolution. Harmonically, the verse may do nothing or very little. Basically, it is the "calm before the storm" that is the chorus. That doesn't mean it needs to be purposefully boring, only that it doesn't give the listener a sense of completeness. A verse is often composed of a repeating melodic phrase and/or harmonic progression. Often there is no progression at all, with accompaniment playing a groove that solidifies the key of the song.

Some songs also contain a pre-chorus section between the verse and chorus. This is generally brief and serves to build tension that the verse did not create and the chorus will relieve. It may change the key temporarily, or at least change the harmony away from the tonic if the verse uses a groove or shuffle that lacks or has a very limited progression.

The chorus is used as a burst of excitement in the song. It is generally shorter than the verse, consisting of a single harmonic progression. The chorus usually creates its own tension as well as relieves it, or it may serve as a somewhat complex method of relieving the verse's tension. If the progression repeats it is often only to use a different ending with a stronger resolution. The chorus usually employs larger sonic textures than the verse - "bigger" chords covering more octaves or a shift to distorted guitar tones, louder and more resonant cymbals, and background vocals to name a few. Its melodies are often more intricate and cover larger note ranges than the verse, establishing more tension, then relieving it. Choruses often resolve their tension in their final melodic line, which is called "the hook", which derives its name from how it captures the listener's attention and is a short memorable line that listeners can sing to themselves.

Where modulation occurs in rock music is often to the IV or iv key on a repeat of the chorus. This increases the impact of the chorus without changing its content. In some cases, the verse and chorus will be written in different (but highly-related) keys.

A non-repeating bridge section often occurs between an occurrence of the chorus and the final verse-chorus or just the chorus. These are designed to create contrast with the rest of the song but can take a variety of forms. Sometimes it continues the intensity of the chorus but uses a different harmonic theme that builds tension which is released by the ensuing chorus. Sometimes it is completely slow and boring, a kind of super-verse to serve as calm before the intensity of the chorus. Sometimes it is its own complete, yet somewhat brief, musical statement, serving as the climax of the song.

Guitar solos are usually performed during the bridge. Other common placements are over instrumental repetitions of the chorus (or verse (and prechorus) and chorus).

Some songs have intro's or outro's played at the beginning or ending of the song but nowhere else, which are also common places for guitar solos.

Blues Influence

Rock is strongly influenced by blues. If you notice, the minor pentatonic scale is the same as the blues scale but missing the tritone. Rock is historically an outgrowth of African-American blues merged with swing, country, folk and other genres.

This blues influence has never been completely separated from rock - even modern heavy metal often incorporates some aspects of blues playing. Melodic conventions, blue notes, I - IV - V - I modulations, slow-moving or static harmonies, are all derived from blues backgrounds.

The main technical difference between the two is that rock is more energetic and dance-oriented than blues. Following this, rock is more up-tempo and incorporates a back-beat with the snare. Vocal timbres are often more lively or outright screams. While blues has been fairly traditional in its approach, rock has been more experimental, leading to a wide variety of harmonic progressions, song structures, timbres, and melodies. Thus, rock has a much larger number of sub-genres.

Four Chord Songs: I - V - vi - IV

A simple 3 or 4 chord progression is typical for rock songs, and often strong cadences such as the (V - I) are avoided. One of the more popular progressions is I - V - vi - IV. Remember that one of our example progressions when discussing harmonic function was I - vi - IV - V, which moves from tonic to pre-dominant to dominant function, before resolving back to the I. The I - V - vi - IV progression on the other hand, moves basically in reverse: tonic, dominant, pre-dominant. Its transitions are natural but do not present a strong resolution. When the progression repeats, there is not a strong resolution when returning to I, and the progression seamlessly repeats over and over.

Axis of Awesome's 4 Chord Song uses this progression. You can hear the effect I'm talking about above. And you can see its popularity, being used in dozens and dozens of recognizable songs.

Sub-Genres

Rock and Roll started out as basically a fusion of different genres in the 1950's. Since The Beatles and the "British Invasion", it became extremely popular and spawned a number of different sub-genres:

Alternative - Alternative came around in the early 1990's as an attempt to move away from the technicality, pop-influence, "cheesiness", and synthetic "perfection" of the 80's. It featured a return towards folk and classic rock styles, yet the sound had a more modern edge due to more advanced production and playback technology. Vocal ranges returned to the normal range of most humans compared to the high-pitched vocals popular in the 80's. Guitar riffs were made simpler and less prominent. Guitar timbre features more clean and slightly broken up tones - heavy distortion was often nasty and rough instead of smooth and searing like the 80's.
- Examples: Nirvana, Better than Ezra, Spin Doctors, Alanis Morisette
Alternative or Nu Metal - Appeared in the late 90's as an outgrowth of alternative rock, particularly grunge. It incorporates the more downtrodden vocal stylings and modern sound of alternative rock with the riffing and rhythms of heavy metal. Yet it goes further by favoring down-tuned guitars and frequent usage of completely screamed vocals. Many groups also incorporated rapped vocals. While starting out as an underground movement, it eventually became mainstream and lost much of its identity in the process.
- Examples: Korn, Limp Bizkit, Deftones, Disturbed
Black Metal - Incorporates the blast beats and extreme sound of death metal with synth/symphonic elements and neoclassical songwriting. Guitars are distorted and provide thick textures such as in doom metal, but without any emphasis on down-tuning. Vocals are often screamed and snarled.
- Examples: Cradle of Filth
Blues-Rock - Although all rock and roll is strongly influenced by (and in fact an outgrowth of) blues, blues-rock is a term that came about to describe artists whose compositions were structurally based solidly in blues but used rock instrumentation and rhythms.
- Examples: B.B. King, George Thorogood, Stevie Ray Vaughn, Jeff Beck, Kenny Wayne Shepherd, Gary Moore, Eric Clapton
Classic Rock - With rock and roll expanding into a number of sub-genres as early as the late 60's, the term classic rock was created to describe rock groups of the 60's, 70's, and even some 80's. It generally refers to the more popular and mainstream artists
Death Metal - A more modern subgenre of heavy metal, death metal features a very extreme sound and style employing fast dissonant guitars usually playing in diminished scales, gutteral vocals, disjointed rhythms, and blast beat drumming.
- Examples: Cannibal Corpse, Dying Fetus
Djent - Debatably called a sub-genre vs. a style of playing, djent is an outgrowth of metalcore using extremely down-tuned guitars (typically down-tuned 7 strings or 8 strings). Its trademarks are funky, off-beat accented riffs; heavy use of syncopation between instruments; and ambient clean guitars.
- Examples: Periphery, Tesseract
Doom Metal - Another sub-genre of heavy metal, doom uses slower tempos and large distorted chords on downtuned guitars to create a dissonant, dark atmospheric tone, combined with simple, chant-like melodies or sustained screamed vocals. Rhythms are rather straight-forward, signaling an unending march towards oblivion.
- Examples: Allogoch, Opeth, Eyehategod, Exhorder, Crowbar
Emo - A sub-genre of alternative that focused on deeply emotional themes such as loss of innocense, death, and failed relationships. Quirky and silly elements from alternative were dropped, while the simpler songwriting and punk-styled vocals were kept. Musically, focus was given to harmony and melody over rhythm. Drums were used to keep simple time and emphasize sections rather than provide dance-able grooves.
- Examples: Dashboard Confessional, Brand New
Grunge - A sub-genre of alternative, this was almost a protest of 80's music, having a kind of punk element. It replaced 80's cheesiness with quirkiness, featuring uncomfortable screaming, crying, whining, noise, or other unsettling soundscapes. Rather than focus on poppy one-line hooks in choruses, grunge would focus on depressing or brooding melodies, often with double-tracked or processed vocals. Guitars and bass were often distorted using a raucous fuzz distortion.
- Examples: Nirvana, Stone Temple Pilots, Veruca Salt
Hair Metal (80's Metal) - Continuing the popularity of 70's Heavy Metal, Hair Metal focused on making the extremes of heavy metal more extreme: heavier distortion on guitars, larger and more intricate riffs, heavily technical and swift guitar solo's, high-pitched shrieking vocals, and cutting edge production techniques involving tape delays, rich simulated reverb, and synthesized drums.
- Examples: Extreme, Def Leppard, Poison, Warrant, Motley Crue
Hard Rock - Hard Rock basically started out as interchangeable with Heavy Metal, describing the rock bands of the 70's that favored using greater distorted guitar and dirty vocals than their contemporaries. As time went on, heavy metal evolved into a number of more extreme sub-genres, diverging from and leaving the original blues-based sound in kind of an ambiguous label, which is now called Hard Rock. New Hard Rock groups were popular throughout the 70's and 80's, fizzled out in the 90's, but have been regaining more and more popularity since.
- Examples: AC/DC, Mountain
Hardcore (Punk) - An outgrowth of the 70's punk rock movement that incorporated the more extreme of metal elements, favoring rhythm over melody and abandoning common song structures. Vocals were often screamed or shouted and guitars were heavily distorted.
- Examples: Black Flag, Hatebreed
Heavy Metal - Heavy Metal began in the 70's with groups that pushed rock and roll into a harder edge, featuring heavily distorted guitars, more involved drums, and screeching vocals. Rather than establish simple shuffles, the guitars would establish tonality through more complex riffs.
- Examples: Led Zepplin, Black Sabbath, Judas Preist
Instrumental Guitar Rock - With the appearance of exalted guitar players such as Jimi Hendrix, Jimmy Page, Eddie Van Halen, and Randy Rhoads, rock began to place higher value on virtuosic caliber guitar playing in the 80's, often known as shredding. Some players branched out to release solo records that had no or little vocals, instead using lead guitar throughout the songs serving to play the songs' melodies, which were often embellished as though every song was a giant guitar solo. The general song-writing followed the inspiration of Hair Metal, which is what most of these musicians were playing before starting their solo projects. Songwriting featured similar dramatic crescendos, sensationalized choruses, reverb-laden rhythms, and upbeat bluesy riffs; and many albums had contrasting ballads.
- Examples: Joe Satriani, Paul Gilbert, Yngwie Malmsteen, Steve Vai
Melodic Death Metal - An outgrowth of death metal found particularly in Scandinavia, this sub-genre incorporated far more melody in guitars and sometimes vocals, as well as neo-classical elements into songwriting in contrast to death metal's atonal or dissonant scales.
- Examples: In Flames, Soilwork
Metalcore - Another sub-genre of metal, metalcore focused on uniting the elements of thrash-metal inspired guitar riffs and drumming with the modernity, aggressiveness, vocal-styles, and rhythms of hardcore.
- Examples: Killswitch Engage, Unearth, Lamb of God
Pop-Punk - A mixture of the pop nature of Alternative rock mixed with the vocal tone and up-tempo speed of punk. Musically, the songwriting was more traditional and less extreme than older punk, with the tempo slowed down a bit and sections having less contrast. Rather than feature the anti-establishment angst of the punk movement, pop-punk generally focuses on humor or the monotony of everyday life. This made it much more radio-friendly and accessible to the mainstream, where it enjoyed huge success.
- Examples: Green Day, Blink 182
Progressive Rock - Seeking to escape the simple foundations and song structures of rock's blues influence, groups started experimenting with evolving themes, more complicated song structures, odd-time signatures, and greater exhibition of technical abilities, creating progressive rock in the 70's.
- Examples: Genesis, Rush, Pink Floyd
Progressive Metal - Adds the experimental and complex elements of progressive rock with the extreme elements of heavy metal. Following this paradigm, one could basically place "progressive" in front of any sub-genre of heavy metal and find a couple of bands that fit. However, because such groups are relatively rare compared to their parent genres, this one sub-genre lumps them all together. For example, the prominent progressive metal act is Dream Theater; however, they take a strong Hair Metal influence in comparison to Opeth, who take a strong Doom Metal influence.
- Examples: Dream Theater, Opeth, Meshuggah, Periphery, Protest the Hero
Punk -
- Examples: The Ramones, The Sex Pistols
Power Metal -
- Examples: Iron Maiden, Dragonforce
Raggae -
- Examples: Bob Marley and the Whalers
Screamo - Essentially a mixture of emo with Alt-metal and Hardcore, screamo is basically emo's angrier brother. Retaining the same lyrical themes as emo, screamo embellished the depression of emo with rage. Musically, screamo heavily resembles alt metal, with the main difference being a lack of quirky sections or dance-able beats. Another common staple is contrasting sections of calm and chaos, with vocals going from clean to extreme screams, guitars going from clean or quasi-clean to fully distorted, and drums going from light and soft to thick and aggressive. Many groups used 2 vocalists, one singing in a grunge/alternative/emo clean style and the other dedicated to screaming.
- Examples: Thursday, Poison the Well, Alexisonfire
Ska -
- Examples: Mighty Mighty Bosstones
Soft Rock -
- Examples: Rod Stewart, Bruno Mars, Billy Joel
Thrash Metal - While Hair Metal took a pop-direction in the 80's, Thrash Metal took an underground direction, with less focus on catchy vocal hooks or even recognizable chorus sections. Thrash focused on speed, screamed vocals (sometimes even without pitch), and unsettling lyrical topics such as nuclear war and black magic. Guitar riffs were fast and often focused on chugging open string palm mutes.
- Examples: Metallica, Megadeth, Slayer, Exodus, Pantera