Question:  Poème élégiaque in D minor was dedicated to a composer whose best-known works are "Pavane", "Après un rêve" and what? 
Sentence (from "Trois mélodies, Op. 7 (Fauré)"): They were not, however, originally conceived together as a set of three; the opus number 7 was imposed on them retrospectively in the 1890s, almost 20 years after their first publications.
Relevant evidence: No