Johann Sebastian Bach (1685-1750) was a German composer and instrumentalist, who was a particularly talented organ player.
Bach's Toccata and Fugue in D minor was originally written for the organ and was not published during his lifetime. A transcription (re-writing) of the composition for piano was made by Ferrucio Busoni (1866-1924).
Since the 1970s, the attribution of the original work to Bach has been questioned by several scholars.
Listen here to the Busoni transcription of Bach's Toccata and Fugue in D minor on Spotify.