Matisse’s Piano Lesson, 1916 (Museum of Modern Art, New York). It depicts the painting Woman on a High Stool (Germaine Raynal), 1914, also at MoMA, and a number of other works. Matisse’s son Pierre, the student , was actually sixteen at the time of the painting, but this, like much of Matisse’s work, looks back, not to a “slice of time”, a single moment, but to something about a space and an instrument and at least two people and possibly quite a lot of time, to relationships that are personal, but not just personal. It is silent. And perhaps the silence of what Flusser calls a traditional image, imposed by the painter on the materials, is heightened if the cause of the painting — a cause in the painter’s mind — does involve sound.