Chorus

A performance where the audience is the instrument. Everyone raises their phone, and as the performer plays, hundreds of phones sound together — low voices on one side of the room, high voices on the other, all landing on the same beat. The audience becomes a choir spread across every seat.

The piece leans on three Starfish features:

Presence to sort phones into voices and show the performer the balance of the room.
Broadcast to send each cue to every phone at once.
Clock sync so all of them play on the same beat.

Presence — voices in the room. Each phone picks a voice and announces it, and the performer's screen shows how the sections fill up.

await client.join("chorus");
await client.clock.sync(); // aligns each phone to the shared beat

const myVoice = pickVoice(); // "bass" | "tenor" | "alto" | "soprano"
client.presence.set({ voice: myVoice });

// On the performer's client:
client.presence$.subscribe((room) => updateSectionMeters(tally(room, "voice")));

Broadcast + clock — everyone on the beat. The performer sends a cue to the whole room: a voice, a note, and a moment just ahead. Every phone in that voice plays exactly then.

// Performer's client:
function cue(voice, freq) {
  client.broadcast(
    { voice, freq, at: client.clock.now() + 500 }, // half a second ahead
    { delivery: { reliability: "latest" } },        // if the network lags, use the newest cue
  );
}

// On each phone:
client.messages$.subscribe((frame) => {
  const { voice, freq, at } = frame.payload;
  if (voice === myVoice || voice === "all") client.clock.runAt(at, () => playTone(freq));
});

The performer can also cut the whole room to silence, marking the cue critical so a server can prioritize it over ordinary traffic.

client.broadcast({ voice: "all", stop: true }, { priority: "critical" });

One performer, hundreds of phones, a single chord no speaker could make alone.

Chorus ​

Chorus