The blues: twelve bars and blue notes

The blues was born in the late 19th century in the American South, especially in the Mississippi Delta, among the descendants of enslaved Africans. After abolition (1865) most of them still lived in poverty, working in the cotton fields under segregation. Their music inherited work songs, the cries called out in the fields (field hollers), the spirituals sung in church and the call and response that came from Africa. The blues sings of sorrow, lost love and injustice, but also of humour and the will to hold on.

Music of singer-guitarists… and of women singers

The first bluesmen played alone, a guitar on their knees, at parties, at railway stations, in juke joints. The composer W. C. Handy recalled hearing, around 1903 at a Mississippi station, a guitarist sliding a knife along the strings as he sang; in 1912 he published The Memphis Blues, one of the first printed blues. In 1920 Mamie Smith's record Crazy Blues sold hundreds of thousands of copies: record companies discovered an African American audience. The 1920s belonged to the great women singers of "classic blues", accompanied by pianists and jazz bands: Ma Rainey, Bessie Smith. At the same time the Delta bluesmen (Charley Patton, Son House, then Robert Johnson in 1936–1937) recorded alone with their guitars.

The 12-bar progression

The heart of the blues is a 12-bar chord sequence on three chords: I, IV and V of the key (see 12-bar blues). In C that means C7, F7 and G7. The progression below is the most common (there are many variants):

M:4/4
L:1/4
Q:1/4=100
K:C
"C7"[CEG_B]4 | "C7"[CEG_B]4 | "C7"[CEG_B]4 | "C7"[CEG_B]4 |
"F7"[C_EFA]4 | "F7"[C_EFA]4 | "C7"[CEG_B]4 | "C7"[CEG_B]4 |
"G7"[DFGB]4 | "F7"[C_EFA]4 | "C7"[CEG_B]4 | "G7"[DFGB]4 |]

The lyrics often follow an AAB form: a first line sung over bars 1–4, repeated over bars 5–8, then an answering line that wraps things up over bars 9–12. Between the sung phrases the guitar or piano "answers": call and response again.

Blue notes

The blues uses notes that lie "between" the piano keys: the third, fifth and seventh are often sung a little flat, or slid into. These are the blue notes. On the piano you approach them with the blues scale (C, E♭, F, F♯, G, B♭) and by letting E♭ rub against E; on the guitar you bend the string or use a bottleneck slide. Here is the scale, followed by a short phrase written for this lesson:

M:4/4
L:1/8
Q:1/4=90
K:C
C _E F ^F G _B c2 | "C7" z _E =E G _B2 G =E | C8 |]

Blues piano and boogie-woogie

In the bars and lumber camps of Texas and the South, pianists invented a left hand that rolls non-stop in repeated eighth notes over the 12-bar progression: boogie-woogie. In 1928 Pinetop Smith recorded a piece that gave the style its name; in the 1930s Albert Ammons, Meade Lux Lewis and Pete Johnson made it a hit in New York.

Electric blues and beyond

In the 1940s millions of African Americans left the South for the cities of the North. In Chicago Muddy Waters, Howlin' Wolf and their musicians plugged their guitars into amplifiers and added drums, bass and amplified harmonica: this was Chicago blues. B.B. King made his electric guitar sing like a voice. In the 1960s young British musicians who were mad about these records (the Rolling Stones, who took their name from a Muddy Waters song, Eric Clapton…) reinvented them: without the blues there would be no rock, no soul and much less jazz.

What to listen for

• 12-bar phrases coming round again, on three chords.
• "Bent" or slid notes, between major and minor.
• An often swung rhythm (the shuffle: long-short eighth notes).
• Call and response between voice and instrument.

Listening list

• Bessie Smith (1920s), Robert Johnson (1936–1937), Muddy Waters (1950s), B.B. King live.
• The boogie-woogie of Albert Ammons and Meade Lux Lewis.