Bluegrass music is a form of American roots music with its own roots in the English, Irish traditional music and Scottish traditional music of immigrants from the British Isles (particularly the Scotch-Irish immigrants of Appalachia), as well as the music of rural African-Americans. It was this tradition that A.P. Carter used and collected for the songs played and written by the Carter Family. Bluegrass songs are played with each melody instrument switching off, playing the melody in turn while the others revert to backing; this is in contrast to Old-time music, in which all instruments play the melody together or one instrument carried the lead while the others provide accompaniment.

Bluegrass as a style probably developed sometime in the 1930s. As with any musical genre, no one person can claim to have "invented" it. Rather, bluegrass is an amalgam of old-time music, blues, ragtime and jazz. Nevertheless, there is clearly a founding father, Bill Monroe. The bluegrass style was named for his band, the Blue Grass Boys , formed in 1939. Monroe's 1945-48 band, which featured banjo player Earl Scruggs, singer/guitarist Lester Flatt, fiddler Chubby Wise and bassist Cedric Rainwater, created the definitive sound and instrumental configuration that remains the model to this day. Unlike mainstream country music, bluegrass continues to rely on acoustic stringed instruments: The fiddle, banjo, acoustic guitar or folk guitar, mandolin, and upright bass are sometimes joined by the dobro (also known as a resophonic guitar or steel guitar), and a bass guitar is occasionally substituted for the upright bass. This instrumentation originated in rural black dance bands and was being abandonded by those groups (in favor of blues and jazz ensembles) when picked up by white musicians (van der Merwe 1989, p.62).

Besides instrumentation, the distinguishing characteristics of bluegrass include vocal harmonies featuring two, three, or four parts, often featuring a dissonant or modal sound in the highest voice (see modal frame); an emphasis on traditional songs, often with sentimental or religious themes; and improvised instrumental solos.

Notable artists:

• Bill Monroe
• Jimmy Martin
• Flatt and Scruggs
• Doc Watson
• Del McCoury
• John Hartford
• Lester Flatt
• The Stanley Brothers
• The Seldom Scene
• Ricky Skaggs
• Alison Krauss
• Hazel Dickens
• Rhonda Vincent
• Country Gentlemen
• Johnson Mountain Boys
• Ralph Stanley
• Osborne Brothers

The following are/were also notable bluegrass artists, despite being better known for their contributions to other musical genres:

• Béla Fleck
• Jerry Douglas
• Jerry Garcia (Old and in the Way)
• Dolly Parton
• David Grisman
• Nickel Creek
• Gundula Krause

Movies about bluegrass or featuring bluegrass themes:

• O Brother, Where Art Thou?
• That High Lonesome Sound
• Deliverance
• Harlan County, USA

Reference

• van der Merwe, Peter (1989). Origins of the Popular Style: The Antecedents of Twentieth-Century Popular Music. Oxford: Clarendon Press. ISBN 0193161214.