Intro to Blues
Blues originated in the African American communities in the late 19th and early 20th centuries, mainly in the Southern U.S. It evolved from African musical traditions, work songs, spirituals, and folk music, often reflecting themes of struggle, emotion, and resilience. Blues is characterized by its specific chord progressions often in the 12-bar format, and the expressive “blue” notes, which convey emotion and sorrow. Blues laid the foundation for many other genres, including jazz, rock, and soul.
12 bar blues
The 12-bar blues is a common chord progression in blues music, using three chords: the tonic (I), subdominant (IV), and dominant (V). It is typically divided into 12 bars, and we keep repeating this 12 bars. The 12 bar following this pattern: 4 bars of I + 2 bars of IV + 2 bars of I + 1 bar of V + 1 bar of IV + 2 bar of I . Sometimes we adjust last two bars of I to one bar of I + one bar of V.
The 12-bar blues is the foundation of many blues songs and has influenced genres like rock and jazz. Jazz often uses this structure, especially in early jazz. While jazz features complex harmonies and improvisation, the 12-bar blues offers a simple structure for musicians to improvise. Jazz musicians may also modify the traditional 12-bar blues to add their own creative touches.
Blue scales
The blues scale is an adaptation of the minor pentatonic scale, the picture above shows the C blues scale. I wrote a separate article about Pentatonic and Blues Scale, if you want to learn more.
Most common keys in Blues
Different instruments favor certain keys based on their tuning and playability, but choosing a key that works for everyone is important for a smooth sound. On piano, keys like C, F, G, and Bb are popular because they are easy to play for blues. For guitar, keys like E, A, G, and D fit well with standard tuning and open strings, allowing classic blues riffs. E is especially common in traditional blues, as it makes use of open strings. When horn players join, keys like Bb, F, and Eb are often chosen to match the tuning of saxophones, trumpets, and trombones.
In a multi-instrument setup, a blues band might choose Bb or F, which work for horns and are manageable for piano, guitar, and bass. However, in traditional blues, E is the most common key, especially for guitar, because of its ease and resonance.
