For which Christmas song is the singer of The Cowgirl and the Dandy well known ? 
The Cowgirl and the Dandy: "The Cowgirl and the Dandy" is a song written by Bobby Goldsboro and performed by Brenda Lee. Brenda Lee:  She is perhaps best known in the United States for her 1960 hit "I'm Sorry", and 1958's "Rockin' Around the Christmas Tree", a United States holiday standard for almost 60 years.
Rockin' Around the Christmas Tree"