Lewis gradually transformed the group away from strictly 1940s bebop style, which served as a vehicle for an individual artist's improvisations, and instead oriented it toward a more refined, polished, chamber style of music. Lewis's compositions for The Modern Jazz Quartet developed a "neoclassical style" of jazz that combined the bebop style with "dynamic shading and dramatic pause more characteristic of jazz of the '20s and '30s". Francis Davis, in his book "In the Moment: Jazz in the 1980s", wrote that by "fashioning a group music in which the improvised chorus and all that surrounded it were of equal importance, Lewis performed a feat of magic only a handful of jazz writers, including Duke Ellington and Jelly Roll Morton, had ever pulled off—he reconciled the composer's belief in predetermination with the improviser's yen for free will".