Carolyne zu Sayn-Wittgenstein’s unpublished Nouvel essai esthétique was certainly written in the 1860s in Rome. Dedicated to Adélaïde-Louise d’Eckmühl, marquise de Blocqueville, it is composed of 4 chapters presenting both general issues on art and religion, and detailed presentation of nine arts. Among them, the chapter on music contains many ideas strongly connected to Liszt’s writings, e.g. influence of Fétis and Hegel, idea of progress, historicism, harmony, catholic music, symphonic music, opera, writings about music, piano, etc. The present article is a first attempt to establish connections between the Lisztian topics and the catholic-historicist aesthetics of the princess Sayn- Wittgenstein, which can be seen as a privileged source for the Neudeutsche Schule.