2013, Catalog No. 8.572913. Finally, Walcha's completion of "Contrapunctus 18 (Fuga a 4 Soggetti)", i.e. the last fugue of Bach's The Art of Fugue, was recorded by Walcha himself for his stereo cycle of Bach's complete organ works, and again by his former pupil George Ritchie: J. S. Bach: The Organ Works. CD 6, track 11: The Art of Fugue, BWV 1080: Contrapunctus 18 in D minor. Archiv Produktion, 2000, Catalog No. 463712. Performed by Helmut Walcha at the Van Hagerbeer/Schnitger organ of the Grote or Sint-Laurenskerk, Alkmaar, The Netherlands. J. S. Bach: The Art of Fugue. CD 2: Contrapunctus 18 (Fuga a 4 Soggetti). In: Desert Fugue, by Will Fraser – George Ritchie. 2 CD + 1 DVD. Raven CD – Fugue State Films, 2010, Catalog No. FSF-0001. Performed by George Ritchie at the Richard, Fowkes & Co. organ, Pinnacle Presbyterian Church, Scottsdale, Arizona. Scores for transcriptions and original works Walcha's editions of Händel's organ concertos opp. 4 & 7, as well as his organ transcriptions of Bach's "Ricercare a 6 voci" from the Musical Offering and the complete transcription for organ of the Art of Fugue (including the final fugue completed by Walcha), have been published by Schott Music and Edition Peters. Bach's "Ricercare a 6 voci" edition also includes an analysis. G. F. Händel: Orgelkonzerte op. 4, Nos. 1–6. B. Schott's Söhne, Mainz, 1940. G. F. Händel: Orgelkonzerte op. 7, Nos. 1–6. B. Schott's Söhne, Mainz, 1943. J. S. Bach: „Ricercare à 6 voci“ aus dem „Musikalischen Opfer“. Übertragung für Orgel (mit ausführlicher Analyse). Edition Peters, Frankfurt a. M., 1964, Catalog No. EP4835. J. S. Bach: „Die Kunst der Fuge“. BWV 1080. Übertragung für Orgel mit Weiterführung und Beendigung der Schlussfuge. Edition Peters, Frankfurt a. M., 1967, Catalog No. EP8000. The latter editor also published the scores of Walcha's 88 original chorale preludes, in four volumes: Helmut Walcha: Choralvorspiele, Bd. 1. Edition Peters, Frankfurt a. M., 1954, Catalog No. EP4850. 25 chorale preludes for organ; prelude no. 11, Erhalt uns, Herr, bei deinem Wort (Maintain us, Lord, in Thy word), uses the same Lutheran melody used by Bach in cantatas BWV 6 and BWV 126 (1725). Helmut Walcha: Choralvorspiele, Bd. 2. Edition Peters, Frankfurt a. M., 1963, Catalog No. EP4871. 20 chorale preludes for organ. Helmut Walcha: Choralvorspiele, Bd. 3. Edition Peters, Frankfurt a. M., 1966, Catalog No. EP5999. 24 chorale preludes for organ. Helmut Walcha: Choralvorspiele,