The blues is a genre of music that has a rich history, and one of its defining characteristics is the use of the flattened fifth, also known as the "devil's note." It's a unique sound that's been used in countless blues songs. But what is the devil’s note?
The flattened fifth is sometimes referred to as the "devil's note" because of its dissonant and eerie sound. It can make a listener feel uncomfortable or unsettled. In the early days of the blues, this dissonance was a way to express the struggles and hardships of life. It became a symbol of the pain and suffering that many blues musicians experienced, and was used to convey a wide range of emotions, from sadness and despair to anger and frustration.
The flattened fifth, or tritone, has a somewhat controversial history. In the medieval period, the interval was known as the "diabolus in musica" or the "devil in music" and was forbidden by the church. It was associated with evil, and its use was banned in religious music. But the flattened fifth continued to be used in secular music throughout history, eventually finding its way into the blues, in which it was a way for musicians to rebel against the established musical norms and express their emotions freely.
The devil’s note is a musical interval that is created by lowering the fifth note of a scale by one semitone. In the case of the blues, this means lowering the fifth note of the pentatonic minor scale by one semitone. For example, in the key of A, the pentatonic minor scale consists of the notes A, C, D, E, and G. The flattened fifth would be the note D# or Eb, depending on which notation system is used.
One of the most famous uses of the flattened fifth in the blues is in the opening riff of "Cross Road Blues" by Robert Johnson. The riff consists of a repeated pattern of the notes E, A, D, G, Bb, and back to A. The flattened fifth is the note Bb, and it creates a haunting and memorable sound that sets the tone for the entire song.
Another famous example of the flattened fifth in the blues is in the song "I Put a Spell on You" by Screamin' Jay Hawkins. The song features a repetitive, driving riff that centres around the flattened fifth, giving the song a hypnotic and almost trance-like quality.
The flattened fifth has also been used in other genres of music, such as jazz, rock, and metal. In jazz, it is often used to add tension and dissonance to a chord progression. In rock and metal, it is used to create a heavy and aggressive sound.
I teach my students you how to play the blues scale and improvise with it. The devil has the best tunes, and we have great fun playing them!