The Shepard Tone, although discovered academically in 1980s, was used one of J.S. Bach's piece as early as 1744. Bach's "Canon per tonos" from The Musical Offering travels through all twelve minor scales in turn. The king's theme is in the top voice. The lower two voices are in canon, entering a 5th higher (or a 4th lower) at each repetition. C minor, G minor, D minor, A minor, E minor, B minor, F# minor, C# minor, G# minor,... repeating as long as one withes. By the time we get back to C minor, the whole piece is an octave higher than it started.