This website presents the outcomes of the project "Development of a Music Creation System Applying Quantum Gate Circuits", which was supported by the 2018 Mitou (Unexplored) Target Projects – Gate-Type Quantum Computer Division of the Information-technology Promotion Agency (IPA), Japan, from 2018 to 2020. This website also documents subsequent research activities encompassing theoretical, practical, and performative explorations that have evolved from the original project. 

このウェブサイトでは、2018年度未踏ターゲット事業（情報処理推進機構（IPA）／ゲート型量子コンピュータ分野）の支援を受けて2018年から2020年にかけて実施された「量子ゲート回路を応用した音楽創作システムの開発」プロジェクト、及びそれに引き続く開発で得られた理論的・実践的・パフォーマンス的な研究活動について紹介しています。 

Quantum game-based musical interaction

Quantum-Game dual synth (Demo)
Experience a real-time quantum game-based musical interaction system.

 Access: http://qgame.quantum-creation.jp:5050/
（Note: The server may be temporarily stopped for maintenance or updates without prior notice. ）

S.Souma, "Development of an Interactive Sound Generation System Based on Quantum Game Theory," 

Presented at the 3rd International Symposium on Quantum Computing and Musical Creativity (ISQCMC 2025), Palermo, Italy.　https://2025.isqcmc.org/ 

User  Manual

Seats Assignment 

Team / Room ID Mode

• Two players (or one person using two devices/browsers) agree on a Team/Room ID (any string is fine).

• Each player enters the same ID and clicks “Join by ID”.

• If both players join successfully, the system will assign them Seat A and Seat B automatically.

• If Seat shows “SPEC”, it means the ID is currently in use.
  Please enter a different (arbitrary) ID.

Quick Match Mode

• After accessing the page, click “Quick Match”.
  The screen will display “Waiting for another player...”

• When another user also accesses the page and clicks “Quick Match”,
  both users will be matched automatically, and Seat A / Seat B will be assigned at that moment.

After the Seats Are Assigned

Once Seat A/B are assigned, the interaction proceeds as follows:

1. Set Strategies

• Each player selects their quantum strategy parameters (θ and φ) on their client.

• These parameters define the player’s quantum “intention” for the next musical interaction.

• Strategies may be changed at any time before triggering the next measurement.

2. Update the Round (Register Strategies)

• Click “Update Round” to submit your current strategy to the server.
  This action does not produce sound yet — it only updates the strategic state for the next measurement.

• Unlike a fixed turn-taking system, either player can update the round at any moment.
  This flexibility is intentional:
  the timing of this update itself becomes a form of musical negotiation or psychological gameplay.

3. Play Notes (Measurement + Sound)

• When a player presses a key, the server performs the quantum measurement using the most recently updated strategies.

• The measurement outcome (00, 01, 10, or 11) is displayed, and the corresponding pitch shift is applied to the sound that is played.

• Each key press triggers a new measurement, allowing players to experience the interference-based interaction directly through sound.

Typical Interaction Loop

1. Both players adjust θ and φ

2. Press Update Round

3. Play keys → hear quantum outcome as sound

4. Adapt strategy and repeat
   
   

 Short intuitive explanation 

“Update Round” sets the intentions,
“Key press” reveals the interaction result through sound.

Summary of "MITOU" project + α (2018-2021) 

Presentation movie (in Japanese)

recorded in Feb. 7, 2020 as the final presentation of IPA project. 

Sorry that both the slides and presentation are in Japanese, but I believe that basic idea (presented after 0:06:33) will be understandable without understanding Japanese (some demonstrations are also included). 

Research map:  https://researchmap.jp/read0133501?lang=en

Contact: 

Satofumi Souma (ssouma@harbor.kobe-u.ac.jp)

Department of Electrical and Electronic Engineering, Kobe University

問い合わせ先：

相馬聡文 (ssouma@harbor.kobe-u.ac.jp)

神戸大学大学院 工学研究科 電気電子工学専攻