[2] This catalog was soon recognized throughout Europe and Santini established contacts with an international range of musicologists, musicians and collectors: Karl Proske, Raphael Georg Kiesewetter, Carl von Winterfeld, Carl Friedrich Zelter and Felix Mendelssohn Bartholdy.
In 1835, through cardinal Odescalchi, Santini became a member of the Congregazione e Accademia di Santa Cecilia; in 1837 of the Sing-Akademie zu Berlin, in 1845 of the Mozarteum in Salzburg and in 1840 of the French Comité historique des arts et monuments du Ministére de l'Instruction Publique.
There, Santini started to organize weekly private music soirées where pieces from his precious collection were executed.
Between 1830 and 1840 Santini's economic condition became difficult and he considered for the first time selling his collection which then numbered 4.500 handwritten and 1.200 printed scores.
In Münster the collection was deposited in the Episcopal Museum of Christian antiquities and fell into disuse and was forgotten for many years.
Some of his handwritten letters and scores are also kept in the library of the Conservatorio Giovanni Battista Martini | liceo musicale di Bologna[3]