David is a prominent member of Ingpen Williams an artist's management firm in London. Founded in 1946 by Joan Ingpen, and her dog Williams, the business passed into the hands of Howard Hartog when Joan Ingpen moved to Covent Garden as artistic administrator at the request of Sir Georg Solti. She subsequently held similar positions at the Paris Opéra and the Metropolitan Opera New York. During the second half of the twentieth century, the company represented many of the greatest artists of the time, including Sir George Solti, Pierre Boulez, Rudolf Kempe, Sir Michael Tippett, Dame Joan Sutherland, Elisabeth Söderström, Christa Ludwig, Geraint Evans, Hans Hotter and Alfred Brendel. Boulez and Brendel remain on the list today. Ingpen and Williams has adapted to the twenty-first century without losing any of the traditions of long-term personal management that have always been at the heart of the company. It has maintained a scale of operation, which allows the firm's individuals to communicate with each other, with its artists and with those throughout the world who wish to engage its artists.