在這篇論文中，我們希望可以完美合成從複音音樂中擷取的單音，我們使用TE-LPC合成法，它比傳統語音所使用的LPC合成法更適用於音樂合成，因為LPC是針對formant做逼近，但TELPC是針對harmonic partials做逼近，由於音樂訊號中partials的分布情況會影響訊號的音色，故使用True Envelope來模擬，如此一來，可以使得合成音具有原本音樂訊號的音色。此外，在傳統的TELPC合成法使用的是固定的frame size及hop size這會使合成音發生振幅不穩的現象，故此篇論文使用適合該音樂訊號的frame size及hop size，藉此改善振幅不穩的問題。在此架構下，我們可以像創作家玩音樂，改變音樂的內容，甚至是改變原本音樂家的風格。

In this thesis, I presented a flexible analysis/re-synthesis method for smoothly changing the properties of isolated notes in polyphonic instrumental music recordings. True Envelope Linear Predictive Coding (TELPC) method has been employed as the analysis/synthesis model in order to preserve the original timbre quality as much as possible due to its accurate spectral envelope estimation. I modified the conventional LPC analysis/synthesis processing by using pitch synchronous analysis frames to avoid the severe magnitude modulation problem. Smaller frames can thus be used to capture more local characteristics of the original signals to further improve the sound quality. In this framework, one can manipulate a sequence of isolated notes from commercially available polyphonic instrumental music recordings and interesting re-synthesized results are achieved.

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