Polychoral
Style with several separate sound groups.
What it means
Polychoral describes music written for two or more separate sound groups. Each group is complete in itself, so that it can sing or play alone; together they form a very large ensemble. The groups can consist of singers, of instruments, or of both, and are often placed spatially apart from one another.
Musical use
The polychoral style has its best-known form in Venetian music around 1600, where the layout of the churches with several galleries favoured the practice. The musical appeal lies in the interplay: the groups toss short motifs to one another, overlap, and unite at climaxes into the full sound. This creates a form that rests on contrast and intensification rather than on continuous polyphony. The technique continues to have effect, for instance in double-choir motets of later periods and in orchestral works with spatially distributed groups.
Performance practice
Clarify the placement early, for it determines the effect and the degree of difficulty: the further apart the groups stand, the more strongly the travel time of sound makes itself felt, and the more one must make music by the direction rather than by ear. Agree on unambiguous signals for entries and rehearse the seams separately. Watch for the same tone colour and volume in all groups, so that the alternation works as movement and not as a break. Check the balance from the audience area.
Bear in mind that the spatial effect is part of the composition: whoever places all groups next to one another forgoes the appeal of the genre but has to struggle less with travel times. Weigh this and rehearse in the chosen placement. With separated placement, plan for several conductors or assistant conductors if there is no visual connection. Take into account that Gabrieli's choirs are often scored at different heights, for instance a high and a low choir. Check the balance from the audience area and clarify whether additional help with direction is needed, such as a second cueing person.
Clarify whether a second person helps with giving entries, if the groups stand far apart and one director alone does not suffice.