The Passacaglia for Violin and Viola was a musical piece composed in the late 19th century and based on an earlier work by Georg Friedrich Händel. Data, together with his "mother" Juliana Tainer, performed the Passacaglia for Violin and Viola during a concert aboard the USS Enterprise-D in 2370. Data played the violin, Tainer the viola. The performance of this piece provided Data with a hint to his later discovery that Tainer was actually a Soong-type android. (TNG: "Inheritance" ) Passacaglia for Violin and Viola was composed by Johan Halvorsen.