Due to a lack of detailed records, little is known about Swiss folk music prior to the 19th century. Some 16th-century lute tablatures have been reconstructed into authentic instrumental arrangements; however, the first major source of information comes from 19th-century collections of folk songs, and work done by musicologist Hanny Christen. One of the oldest varieties of folk music was the Swiss song Kühreihen, an agricultural Alpine song in the Lydian mode. Traditional instruments included alphorn, hammered dulcimer, fife, hurdy-gurdy, castanets, rebec, bagpipe, cittern and shawm.