Blues-based music is a genre of music that originated in the African-American communities of the southern United States. It is characterized by its use of the blues scale and specific chord progressions, as well as specific musical instruments such as the guitar, harmonica, and piano. BOOGIE is a subgenre of blues-based music that is characterized by a steady, repetitive rhythm and a strong bass line. It is often used to accompany dancing and is popular in juke joints and other informal gatherings.