Twelve-Bar Blues

The Beatles recorded an improvised jam session called "12-Bar Blues." Lennon and McCartney frequently commented that they enjoyed covering songs that were basically "12.bar blues" in structure and chord progression. Most guitarists learn about the "12-bar blues" early on in their studies of the instrument. This article describes what the "12-bar blues" is all about and how it relates to the rock and roll era, which the Beatles enriched and then changed forever.

"The Blues" come from African-American roots in the deep South of the US, notably New Orleans and Memphis. Urban versions sprang up in more modern times in the larger cities all over the North American continent. Genres such as gospel and jazz also enriched the creative mix, leading to "rhythm & blues," essentially an urban development within African-American culture, and later, to "rock and roll."

Two prominent features of the "blues" are:

Structured Lyrics: Traditional blues songs had several verses of four-lines of free-flowing text, almost always without refrains. Often the last verse repeated the first verse for song closure. Line two was always a repeat of line one. The third line was some sort of elaboration of the simple statement made in line one, and the fourth would be a simple conclusion -– a kind of intuitive, "folk" version of dialectic thinking. The first verse of "Poppa's Blues" (written by Andrew Lloyd Webber for Starlight Express) makes this clear:

The first line of the blues is always sung a second time
The first line of the blues is always sung a second time
So by the time you get to the third line
You've had time to think up a rhyme.

The subject matter of the blues was usually some sad or melancholy topic, but not always. Occasionally a traditional blues song could be humorous, or even happy. As blues were morphed into rock and roll, employing more upbeat tempos and focusing more on the beginning of a love affair (rather than on its conclusion), texts increasingly moved away from "blue" moodiness.

The "Blues Scale": Blues employs pentatonic scales heavily (like playing the black keys on a piano in sequence from C#). Pentatonic scales are considered very intuitive to the human psyche and are prevalent all over the world. They are also quite easy to play quickly on a guitar. Sometimes an extra note, a flatted fifth (often called a "blues note") would be inserted in the scale. The original boogie-woogie bass riff (e.g., E-G#-B-C#-E and back down / A-C#-F-A and back down) is a pentatonic scale, first in E, then in A.

Twelve-bars in 4/4 time were needed to match the chord structure to the songs: Lines 1 and 2 would be played on the tonic (I) (often as the tonic seventh), two bars for each. Then Line 3 would be played on the sub-dominant (IV or IV7) and go back to I (two bars on each chord). The last line would have a bar's worth of the dominant or dominant seventh (V or V7), followed by a bar of subdominant or subdominant seventh (IV or IV7), and then two final bars on the tonic (I). If a "turn around" was desired (to make a transition to another verse or a coda), the last bar would be a V7 instead of I. This classic structure is thus (in E major) : E-E-E-E-A-A-E-E-B7-A-E-B7. (Each chord is played for four beats, i.e., one measure.) Good musicians learned to play the 12-bar blues in every key, as other instruments (like a B-flat trumpet) might also enter the picture. The range and timbre of the singer's voice would also dictate a specific key.

The Transition to Rock and Roll: The pioneers of rock and roll often emerged out of African-American music trends, whether gospel, jazz, or R&B. Chuck Berry, Fats Domino, Little Richard, Lloyd Price and Carl Perkins were storied names from this wellspring. Bo Diddley, Bill Haley and the Comets, Buddy Holley, Jerry Lee Lewis and Elvis Presley were instrumental in bringing the musical form to a broader, national and international audience. The influence of these musical greats on the Beatles was profound: virtually all of the songs in their early performance repertoire were covers of songs from these famous artists.

Many, though not all, of the most famous rock and roll songs from the early era followed the basic structure of 12-bar blues, often relaxing the restrictions concerning the number of measures each chord would be played. Sometimes a chorus or refrain was included. An example is Little Richard's Long Tall Sally, famously covered by the Beatles. The first two lines varied for each verse, but the last two were used as a chorus. The chord sequence is the 12-bar blues all over again.

(I) I'm gonna tell Aunt Mary 'bout Uncle John
(I) He claims he has the misery but he has a lot of fun
(IV) Oh baby, (I)yeah baby,
(V) Wo baby, we'll be (IV) havin' some fun (I)tonight -- (plus a "turnaround").

As with all dynamic musical forms, the 12-bar blues has an almost limitless capacity for variations and modifications. A few are in a minor key. Others from the rock and roll era take advantage of the invention of electric guitars and amps to overlay elaborate lead guitar solos (usually picking notes out of pentatonic scales). Although written for the 1972 musical, Grease, the song Greased Lightnin' is another musical example of how the blues structure was adapted into rock and roll. The song was written with tongue in cheek to serve as a quintessential example of the 1950's rock era song, with the 12-bar blues chord progression and the turnaround made so obvious that they represent clichés of the era they represented.