Matisse considered it to be a particularly important work and later commented that in this canvas he had used black to paint light.

Interior With a Violin by Henri Matisse

He wants that trance now. His mind disengaging, his eyes tuned to color, shape, relationship. He wants to mix paint, squeeze life from a tube, dip his brushes and bring them up full. Now as if conjuring both his former selves and the self he’s about to become, he holds his brushes, each carrying some old story and yet together forming a gesture of anticipation. One color at a time and all at once. Color as his vocabulary of light.