Felix Mendelssohn Bartholdy was a keen correspondent who wrote and received many letters. His incoming correspondence, 1821-47, largely preserved here intact, provides an insight into his professional and private life. It encompasses his career as a composer, and contains discussions on the composing, performing and publishing of music with several musicians and music publishers.
- Composers and other musicians whose letters are represented here include: William Bartholomew, Sir William Sterndale Bennett, Eduard Devrient, Ferdinand David, Joseph Fischhof, Livia Frege, Aloys Fuchs, Ferdinand Hiller, Ignaz Moscheles, Clara Schumann, Louis Spohr, Wilhelm Taubert, and Karl Zelter
- Music publishers include: Edward Buxton, Charles Coventry, Breitkopf & Hrtel, Alfred Novello, and Nicolaus Simrock
- Mendelssohn's own letters to Charles Coventry and Conrad Schleinitz.
There is also a substantial amount of correspondence with Mendelssohn's own family, and that of his wife:
- letters from the composer's father Abraham Mendelssohn Bartholdy, his mother Lea Mendelssohn Bartholdy, his brother Paul Mendelssohn Bartholdy, and his sisters Fanny Hensel and Rebecka Dirichlet
- letters which Felix Mendelssohn Bartholdy, Ccile, and other members of the family wrote to Ccile's family, especially to her mother, Elisabeth Jeanrenaud
- letters from Ccile to Felix Mendelssohn Bartholdy, including letters written during their engagement
- letters written to Ccile by members of the Mendelssohn family after Felix Mendelssohn Bartholdy's death
- letters written by Felix Mendelssohn Bartholdy to his family during his trip to Italy, France and England, 1830-2, often known as the Reisebriefe.
The Green Books also include a significant number of letters from the following: German painter Eduard Bendemann, Senator Franz Bernus, English writer and critic Henry F. Chorley, Carl August Dohrn, Heinrich Drrien, German historian Johann Gustav Droysen, Johann Albrecht Friedrich Eichhorn, Johann Paul Von Falkenstein, Frederick IV (of Prussia), German orientalist Julius Frst, German diplomat Karl Klingemann, lawyer Conrad Schleinitz, theologian Julius Schubring, and General Karl Von Webern.
The shelfmarks of this section are as follows: MSS. M. Deneke Mendelssohn b. 4, b. 13-14, c. 18, c. 25, c. 31-4, c. 38, c. 40-2, c. 97, d. 13, d. 18-21, d. 28-53, d. 55, MS. Autograph b. 10.