Bluegrass music is a form of American roots music, and it is a sub-genre of country music. It has its own roots in Irish, Scottish and English traditional music. Bluegrass was inspired by the music of immigrants from the United Kingdom and Ireland (particularly the Scots-Irish immigrants in Appalachia), as well as jazz and blues.
Bluegrass pioneer Bill Monroe characterized the genre as: "Scottish bagpipes and ole-time fiddlin'. It's Methodist and Holiness and Baptist. It's blues and jazz, and it has a high lonesome sound."
In bluegrass, as in jazz, each instrument takes a turn playing the melody and improvising around it, 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 carries the lead throughout while the others provide accompaniment. Bluegrass is distinctively acoustic in instrumentation, not using electrical instruments of any kind.