This hypothesis rests in part on the assumption that Fantosme integrated some characteristics of Occitan verse (perhaps coblas by the troubadour Jaufre Rudel) he encountered during a stay in Poitiers in the 1140s, where he probably studied under Gilbert de la Porrée.
He created the role of Nick Carraway in John Harbison's The Great Gatsby in 1999, that of Jaufré Rudel in Kaija Saariaho's L'amour de loin in 2000, and that of Robert E. Lee in Philip Glass's Appomattox.