The principal elements of Honegger's style are: Bachian counterpoint, driving rhythms, melodic amplitude, highly coloristic harmonies, an impressionistic use of orchestral sonorities, and a concern for formal architecture. His style is weightier and more solemn than that of his colleagues in Les Six. Far from reacting against German romanticism as the other members of Les Six did, Honegger's mature works show evidence of a distinct influence by it. Despite the differences in their styles, he and fellow Les Six member Darius Milhaud were close friends, having studied together at the Paris Conservatoire. Milhaud dedicated his fourth string quintet to Honegger's memory, while Francis Poulenc similarly dedicated his Clarinet Sonata.