Baccara is a female vocal duo formed in 1977 by Spanish artists Mayte Mateos (born 7 February 1951 in Logroño) and María Mendiola (born 4 April 1952 in Madrid). The pair rapidly achieved international success with their debut single "Yes Sir, I Can Boogie", which reached number one across much of Europe and became the best-selling single of all-time by a female group, eventually selling more than 18 million copies worldwide. A successful follow-up single ("Sorry, I'm a Lady") and European tour led to a number of album releases, numerous television appearances and the duo's selection to represent Luxembourg in the "Eurovision Song Contest 1978".