Another important break with the past was the radical overhaul of opera by Christoph Willibald Gluck, who cut away a great deal of the layering and improvisational ornaments and focused on the points of modulation and transition. By making these moments where the harmony changes more of a focus, he enabled powerful dramatic shifts in the emotional color of the music. To highlight these transitions, he used changes in instrumentation (orchestration), melody, and mode. Among the most successful composers of his time, Gluck spawned many emulators, including Antonio Salieri. Their emphasis on accessibility brought huge successes in opera, and in other vocal music such as songs, oratorios, and choruses. These were considered the most important kinds of music for performance and hence enjoyed greatest public success.