How did Giovanni Gabrieli develop music for divided choirs at St. Mark’s in Venice?

At St. Mark’s Cathedral in Venice, Giovanni Gabrieli developed music for divided choirs—a technique known as cori spezzati (split choirs)—by utilizing the cathedral's spacious architecture to create novel antiphonal effects.12

Building upon the work of his uncle, Andrea Gabrieli, Giovanni composed massive motets that featured the interaction of two or more groups of singers and instrumentalists. He pioneered a new approach to musical color and orchestration by:31

• Specifying instrumentation: He increasingly designated which instruments were to be used and which groups should consist of soloists versus a full choir.3
• Contrasting forces: He pitted different combinations of performers against one another, creating an endless variety of textures.3
• Dynamic variation: In works such as Sonata pian e forte, he provided explicit directions for loud and soft playing, further distinguishing the musical style of each group.3

These compositions, which helped define the concertato style, relied on simple homophonic textures and strong, declamatory rhythms to manage the complex interplay of sound blocks within the cathedral's acoustics.1