Instrumental Duet Instrumental Duet,Piano - Digital Download SKU: A0.886872 Composed by Johann Sebastian Bach. Arranged by Justin M. Ryan. Baroque,Contemporary. Score and parts. 6 pages. Justin M. Ryan #3005409. Published by Justin M. Ryan (A0.886872). Written in 1723 by J.S. Bach, this piano classic has been brought to the 21st Century and arranged for 2 pianos in 2 different keys simultaneously . This 34 measure piece is now in the keys of F major and C major. Short but quaint, the song now explores beautiful harmonies and new possibilities.