Bluegrass bands are musical groups that perform a genre of American roots music known as bluegrass. This style originated in the 1940s and is characterized by its use of acoustic instruments, including the banjo, mandolin, fiddle, guitar, and upright bass. The music often features tight vocal harmonies and fast-paced rhythms, drawing influences from folk, country, and blues. Typically, bluegrass bands perform in a variety of settings, from small local venues to large festivals. They often engage in improvisation, allowing musicians to showcase their skills through solos. Popular bluegrass bands include The Stanley Brothers and Punch Brothers, who have contributed to the genre's growth and popularity.