Rock

Rock and Roll 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.

Often, the guitar is 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.

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 vocals is emphasized, with some styles featuring screaming, processor-based distortion, or even pitchless singing (rap, spoken word).

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 rather than as a means to prolong a harmonic resolution. Augmented and diminished chords almost never appear.

Rather than use complex progressions, rock focuses typically focuses on riff-based grooves or shuffles (that have a static harmonic fingerprint) or repeating 3 or 4 chord progressions.

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.

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 even chords - they consist only of root and 5th; they are intervals. Typically, power chords are voiced root - 5th or root - 5th - octave. Rarely, you will see them as the 4-string root - 5th - octave - 5th or the inverted 5th - root.

    1  2  3  4  5
g---------7-----12--
d------5--5--5--12--
a---5--5--5--5--10--
e---3--3--3-----10--

1. 2 string
2. 3 string
3. 4 string (2 octave)
4. inverted
5. inverted 4 string (2 octave)

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

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.