A Web-Based Remote Ensemble System

[[abstract]]合奏在音樂學習或是表演上都是不可或缺的一環，成功的合奏需要經過一段時間的練習，而合奏練習，往往必須在現場與其他樂手旋律配合下才能進行。然而，全部樂手能配合的時間不易安排與樂手所在地區並非鄰近，使得練習次數無法增多。隨著Web2.0的到來，網路儼然已成為影音資訊交流與分享的最佳途徑。若以網路作為一個訊息交換與協同合作的平台，合奏練習將不再受限於時間與空間，可透過系統的簡易操作與同步技術達成合奏的效果。 本論文探討合奏與影片同步的問題，並實作一個概念性的網路合奏應用。合奏曲起頭有齊奏與非齊奏的差異，若是齊奏曲，本系統會運用Firefox Audio API的音訊偵測技術自動找尋出各聲部的起始點，以進行同步合奏。若是非齊奏的曲子，則會有各聲部在不同時間進入合奏的問題。除了仰賴系統自動偵測各聲部的起始點之外，還須倚靠人工定義較慢進入樂曲聲部與主要聲部的同步點，進而讓系統計算出各聲部的起始位置時間，達成同步的效果。此系統不僅提供簡易的方式讓使用者將各聲部樂曲結合在一起，更能讓使用者在使用的同時聆聽與了解到各聲部在合奏時的相對關係，正也呼應了”聆聽”在實際樂曲合奏上所扮演的重要角色。 期望此系統能提高使用者合奏的興趣，而此系統也是資訊分享與交流的絕佳應用，藉由網路多媒體技術與音樂表演的結合，解決時間與空間的限制，讓合奏表演不再侷限於特定的時空，而更富彈性與實用性。[[abstract]]Music ensemble is a must in either music learning or music performance. The experience trying to play with others well helps learner a lot. However, players do not often have other players to play with together when they practice on their own. Time and distance restrict musicians to have much practice. With the advent of Web 2.0, Internet has been the best way of sharing and interchanging multimedia content. If music ensemble and network can be integrated in a platform which supports information sharing and collaborating through easy manipulation and technology of synchronization, it will be a wonderful system. Our research focuses on the issue of video synchronization on music ensemble. There are two kinds of music scores which beginning is tutti or not. If the score is tutti at the beginning, sound detection provided by Firefox Audio API is used to find the onset time automatically and a music ensemble is created. If the score is non-tutti at the beginning, automatic sound detection is not enough and users’ manipulation is required. Then the system will calculate the correct initial time of every video and music can be synchronized well. We hope the system can enhance the fun of music ensemble for music players. The novel application can solve the restriction of time and remote distance and make music ensemble more flexible and practical.[[note]]碩