From his opera Siroe. Arranged by Lavell Mason in 1821, this melody was used for hymn While Shepherds Watched Their Flock, written by Poet Laureate Nahun Tate and the only Christmas hymn tolerated during Church of England services in the 18th century. Probably the reason it survived. For Dutch (literally translated) title De Herdertjes Lagen Bij Nachte: see there.
Westminster Choir [as While Shepherds Watched on Edison Bell]
Victor Oratorio Chorus [idem for Victor]
Trinity Quartet [as While Shepherds Watched Their Flocks By Night]
Mormon Tabernacle Choir [as While Shepherds Watched Their Flocks]
Bobby Darin [idem]
Louvin Brothers [idem]
Blue Diamonds [as While Shepherds Watched Their Flocks By Night]
Lou Harrison [as In Honor Of The Devine Mr. Handel from Homage To Pacifica]
Rick Wakeman [all as While Shepherds Watched]
Kate Rusby [as Sweet Bells]
Coope, Boyes & Simpson [on both tunes]
Some UK versions use a different tune: The Watersons ('77), The Albion Band ('85) and Maddy Prior ('91).