The first instrumental compositions Boismortier published were sonatas for two transverse flutes without bass, of which he wrote eight sets. They document both his development as a composer and the early evolution of the genre itself. The Six Sonates pour II Flutes traversieres Sans Baße Op. 47 (1733) — his last surviving set of such works — are ostensibly in the ‘Italian’ style. The dance-heavy format of the earlier ‘French’ sonatas has been abandoned, and structurally they reflect the influence of Telemann’s Sonates sans Basse à deux Flutes traveres [sic] (the second of their four movements is always a fugue). Set in tonalities comfortable for the baroque flute, these virtually unknown duets are expertly written for the one-keyed instrument and are richly rewarding to perform.