Irish, Scottish and Welsh music have long been a major part of American music, at least as far back as the 18th century. Beginning in the 1960s, performers like the Clancy Brothers became stars in the Irish music scene, which dates back to at least the colonial era, when many Irish immigrants arrived. These included many Scots-Irish Presbyterians, whose music was most "closely related to a Lowland Scottish style" . Celtic-Americans have also been influential in the creation of Celtic fusion, a set of genres which combine traditional Celtic music with contemporary influences.