Bardac was a significant link between Ravel and Debussy. A fellow pupil of Ravel at the Conservatoire, he also studied with Debussy. In 1901 he wrote, with Ravel, some transcriptions of Debussy's Nocturnes; and he was among those who attended the first performance of Pelléas et Mélisande in 1902.
He was the son of Emma Bardac, who was formerly the mistress of Fauré, and who became the second wife of Debussy. Ravel dedicated to her L'indifférent, in Shéhérazade; but when she and Debussy established their liaison shortly afterwards, Ravel took the part of Debussy's first wife, contributing to the rift which separated the two composers until Debussy's death in 1918.
Raoul's sister was Dolly Bardac, to whom Fauré dedicated his Dolly suite in 1896; the second movement of the suite is entitled "Mi-a-ou", apparently with no reference to cats, but because the infant Dolly used to refer to her elder brother as "Messieu Aoul".
Of Raoul, Ravel wrote in 1921: "...c'est un musicien délicat; mais aussi l'un des plus anciens élèves de Fauré, qui avait une grande affection pour lui. S'il n'est pas très connu, c'est bien grâce à son caractère, sinon trop modeste, du moins très distant." (Orenstein , letter 179, to Henri Prunières].