"Ultrafox" is an instrumental jazz piece credited to Django Reinhardt and Stéphane Grappelli as composers. It has no lyrics. It was recorded in April 1935 by Django Reinhardt et le Quintette du Hot Club de France avec Stéphane Grappelly, the Paris gypsy jazz group. The track was first issued on a 78 rpm single, with "Ton doux sourire" as the first release. It belongs to the Hot Club of France repertoire of the 1930s and remains part of the gypsy jazz and swing idiom.
Without a vocal line, the tune rests entirely on its melody and the group's swing pulse, so players approach it as a pure instrumental standard in the gypsy jazz manner. Later recordings include versions by Gypsy Trío, Gypsy Swing Quintet de Liège and Noël Akchoté, which show the piece's continued place in the gypsy jazz and swing repertoire.
