In 1885, Ysaÿe returned to Paris, where he joined the Bande à Franck but also supported the growth of a new aesthetic movement represented by the impressionism of Claude Debussy.
In 1894, he and his brother found engagements with the La Libre Esthétique in Brussels, which offered the residents of the city the opportunity to experience a generous range of displays in both music and the plastic arts.
Although Ysaÿe was an excellent pianist, his fragile health did not allow him to follow the hectic pace of his brother's career and he instead became a professor at the Genève Conservatory of Music.
He wrote symphonies, piano concertos, symphonic poems, and chamber music, principally, as well as a requiem.
While he inherited initially the style of César Franck, his later work revealed a clear influence of impressionism.