A History of Rock

Rock did not start with one record or one inventor. In the late 1940s, Black musicians were already making rhythm and blues with a heavy accent on beats two and four, the backbeat. Wynonie Harris recorded "Good Rockin' Tonight" in 1948, and drummer Earl Palmer played a strong backbeat on Fats Domino's "The Fat Man" in 1949. Gospel added the call and response and the shouted intensity. Country and western added its own guitar styles and song forms.

The blues gave the new music its frame: the twelve-bar form with three chords, the pentatonic melodies and the bent notes. A History of the Blues follows that older story, and The 12-Bar Blues shows the chart bar by bar.

With an electric guitar, the sound does not end at the string. The pickup, the amplifier and the speaker shape it as much as the player does. When the amplifier is pushed hard, the signal distorts, and that rough edge became part of the music. Guitarists such as Willie Johnson, on a Howlin' Wolf recording from 1951, already played with a distorted tone. Link Wray's instrumental "Rumble" from 1958 put that sound in front of a wide audience.

Chuck Berry's "Johnny B. Goode" from 1958 set out the vocabulary of the rock guitarist: double-stop licks, a driving rhythm part and a solo that sounds like a second voice. Even that famous intro has a history. Berry took the opening lick from guitarist Carl Hogan, who played it on Louis Jordan's "Ain't That Just Like a Woman" in 1946. The line from jump blues to rock and roll runs straight through it.

Early rock and roll mostly swings. The eighth notes come in uneven pairs, long then short, the way they do in boogie-woogie and the blues. This is the shuffle, and it gives the music its bounce.

From the mid-1960s, rock bands increasingly played straight eighths: both notes of each pair exactly the same length. The same song played both ways turns from a dance at a party into a march on a stage. It is one of the clearest dividing lines in the history of the style. Swing, Shuffle and Groove lets you hear both feels against the same drums.

A power chord is a root and a fifth, often with the octave added, and no third. That makes it neither major nor minor. The common explanation is that it is easy to play, but the stronger reason is acoustic. Distortion adds new frequencies to every note it receives. With a perfect fifth, those new frequencies line up neatly and the chord sounds thick and solid. With a major third, they clash, and the result turns muddy. The heavier the distortion, the fewer notes a guitarist can stack.

"You Really Got Me" by the Kinks, from 1964, is often described as the first hit built on power chords. Dave Davies got his distorted sound by cutting the speaker cone of his small amplifier with a razor blade. From there, the shape spread through hard rock, heavy metal and punk. The Power Chord page shows the shape on the guitar and lets you hear it.

In C major, the chord on the seventh step is B diminished, an unstable chord that pulls toward C. Lower the B to Bb and you get a solid Bb major chord that does not need to go anywhere. The loop I, bVII, IV, I (C, Bb, F, C) became one of the most recognizable sounds in rock.

The missing leading tone is the key. B sits a half step below C and pulls upward; Bb sits a whole step below and does not. So the return to C sounds like coming home rather than resolving. "Sympathy for the Devil" by the Rolling Stones circles on the same idea with E, D and A, and the long coda of the Beatles' "Hey Jude" uses F, Eb, Bb and F. The Mixolydian Chord Progression explains where the bVII comes from, and the listening block above lets you play it.

In 1965, Bob Dylan started recording with an electric band, and the Byrds released their version of his "Mr. Tambourine Man". The Byrds' twelve-string electric guitar rang without distortion, carrying folk melodies and lyrics on a rock rhythm section. The term folk rock appeared in the press that same year.

The second half of the 1960s split rock into many branches. Psychedelic rock stretched songs out with effects and long solos. Blues rock made the twelve-bar form heavier and longer. Cream's "Sunshine of Your Love" from 1967 even moves the drum accents to beats one and three, which is one reason it sounds so heavy. The Rock and Folk style guide covers both traditions side by side.

Hard rock and heavy metal kept the power chord and pushed the volume, the distortion and the low end further. Progressive rock went the other way, with long forms, changing time signatures and ideas from classical music and jazz. Punk in the mid-1970s stripped everything back again: fast tempos, short songs, three chords and no long solos. The three-chord loop of a garage band and the riff of a metal band both trace back to the same small toolkit.

1. Play an early rock and roll record and tap the eighth notes on your leg. Are they long-short or even?
2. Play a mid-1960s rock song with straight eighths. Clap on two and four and listen to how the snare drives the song forward.
3. Find a song built on I, bVII and IV. Sing the root of each chord and notice that no chord pulls hard toward home.

These prompts are about hearing one decision at a time. No single recording stands for a whole decade of rock.

Rock kept the backbeat of rhythm and blues and the three chords of the blues, then changed what the band did with them. The shuffle became straight, the clean guitar distorted, and the leading tone made room for the bVII.