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| 2. | Dannrheuther, E. | Wagner and Reform. |
| 3. | Edwards, H. S. | Rossini and His School. |
| 4. | Gounod, Chas. | Mozart's Don Giovanni. |
| 5. | Henderson, W. J. | Some Forerunners of Opera. |
| 6. | Henderson, W. J. | A Comment on Opera. |
| 7. | Krehbiel, | A Book of the Opera. |
| 8. | Krehbiel, | Studies of Wagnerian Drama. |
| 9. | Mendelssohn | Stories of the Opera. |
| 10. | Newman, E. | Gluck and the Opera. |
| 11. | Newman, E. | Opera. |
| 12. | Sonneck, O. G. | Early Opera in America. |
| 13. | Upton, Geo. P. | The Standard Operas. |
| 14. | | Victor Book of the Operas. |
| 15. | Introduction—American History and Encyclopedia. | H. E. Krehbiel. |
| 16. | Groves Musical Dictionary. | Pages 446, 454. |
| 17. | Moore Encyclopedia of Music. |
| 18. | Naaman Zwillingsbruder. | Volume II. |
| 19. | Dictionary of Music. | Rieman. |
| 20. | University Music Encyclopedia. | |
| 21. | W. B. Matthews. | History of Music. |