From the 1870s, Moro’s heightened interest in color led the artist to experiment with an abstract composition, the basis of which was a bold, carefully thought out contrast of tones. Some of the Moro abstractions can be called plot, others – exclusively expressive images.
Although the artist never intended to present these experimental works as finished works, he found them interesting enough to be inserted into frames and preserved for the future museum. These paintings include “Sirens” and “Sketch”, approx. 1875-80, who shocked the first visitors to the Museum of Moreau. So Robert de Montesquiu called them “streams of paint, anticipating the fauvist paintings of the students of Moreau-Ruault and Matisse.”