- Felix Salzer papers /
- Series 2: Heinrich Schenker Nachlass /
- Sub-series 1: Study of thoroughbass, analyses of J.S. Bach, miscellaneous notes (Mappe 6) /
- Notes on J.S. Bach's Generalbassbüchlein (and other notes on Generalbass) /
- 6/41 /
- Recto: Two pages from a essay on Marx and music, with corrections (proof) [by Schenker?]