Fugue in G minor, BWV.131a

The Fugue in G minor, BWV 131a, is a piece of organ music attributed to Johann Sebastian Bach. It is a transcription of the last movement of his cantata Aus der Tiefen rufe ich, Herr, zu dir, BWV 131. The cantata is definitely by Bach, while the arrangement for organ is regarded by some authorities (from Spitta onwards) as spurious. The organ version likely originated after the cantata, which was composed in 1707.