This opus number is given to 'Two fantasies and valse' in Britten's handwritten catalogue of works (compiled ca. Jan 1928). There is, however, no manuscript source for this compendium of pieces and it exists only conceptually in Britten's catalogue.
A violin and piano version of Untitled piece in B major (ca. 1923), which was partially orchestrated as Walzt (ca. 1923). The melody was later used in the 'Sentimental saraband' movement of Simple symphony, op. 4.