1992 0-7734-9820-6 Suggested trinitarian symbolism of `Contrapunctus XIX' is compared to the established trinitarian symbolism of the great Eb major (St.Anne) fugue, B.W.V.552/2, and suggested trinitarian symbolism of the C# minor fugue of `Well-tempered Clavier' (I,4). Concludes that `Contrapunctus XIX' is a hymn to the Holy Trinity which Bach may have deliberately left unfinished because of an irregularity in the symbolism of the three persons of the Godhead which was the musical-metaphoric equivalent of the heresy of Montanus.