Bluegrass is a form of American roots music. It has its own roots in Irish, Scottish and English traditional music. Bluegrass was inspired by the music of immigrants from the British Isles (particularly the Scots-Irish immigrants in Appalachia), as well as jazz and blues. 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.