Celtic Woman is an all-female Irish musical ensemble conceived in 2004, which involves an occasionally changing lineup of classical and traditionally trained Irish female musicians. The music arranged by composer David Downes employs a repertoire that ranges from traditional Celtic tunes to modern songs. The group has released twelve albums so far: ‘Celtic Woman’, Celtic Woman: ‘A Christmas Celebration’, Celtic Woman: ‘A New Journey’, Celtic Woman: ‘The Greatest Journey’, Celtic Woman: ‘Songs from the Heart’, Celtic Woman: ‘Lullaby’, Celtic Woman: ‘Believe’, Celtic Woman: ‘Home for Christmas’, Celtic Woman: ‘Emerald Musical Gems’, Celtic Woman: 'Solo', Celtic Woman: 'Decade', and Celtic Woman: ‘Destiny’. Celtic Woman are frequently engaged in world tours, largely across the U.S. and Europe, though they have been to Australia, China, Japan, South Africa, and many other places. Cumulatively, albums by Celtic Woman have sold over 10 million albums & DVDs worldwide, and they have been at the top of the Billboard charts for world music several times. Celtic Woman has been described in the past as "Riverdance for the voice."