As the decade progressed, Poulenc produced a range of compositions, from songs to chamber music and another ballet, "Aubade". Hell suggests that Koechlin's influence occasionally inhibited Poulenc's natural simple style, and that Auric offered useful guidance to help him appear in his true colours. At a concert of music by the two friends in 1926, Poulenc's songs were sung for the first time by the baritone Pierre Bernac, from whom, in Hell's phrase, "the name of Poulenc was soon to be inseparable." Another performer with whom the composer came to be closely associated was the harpsichordist Wanda Landowska. He heard her as the soloist in Falla's "El retablo de maese Pedro" (1923), an early example of the use of a harpsichord in a modern work, and was immediately taken with the sound. At Landowska's request he wrote a concerto, the "Concert champêtre", which she premiered in 1929 with the Orchestre Symphonique de Paris conducted by Pierre Monteux.