臺灣傳統民歌在傳播的過程中，同一首民歌常因「即興唱法」的運用，出現曲調方面的變異；以《思想起》一曲為例，即有超過50 種以上的唱法。因此，「即興唱法」的運用方法和模式，十分值得探討。本論文以陳達所唱《思想起》為對象，透過語音學中常用的聲學分析軟體Praat，由微觀角度分析傳統民歌的歌者，如何藉由「即興唱法」，改變唱法和歌詞的手法，致使民歌具有獨特的「再創造性」，使之產生變異，並因而創新。

Improvisation is likely to change the tune of a folk song during the process of transmission, and consequently, a folk song may appear various versions. For example, there are more than 50 versions of 'sixiangqi' existing in Taiwan; however, improvisation has not yet been fully discussed in respect of its method and patterns in Taiwanese folk song. This paper aims to illustrate how improvisation 're-creates' the tune of a folk song by analyzing the tune and its relation to the lyrics in Minnan. Therefore, we look at how the idea of 're-creation' has been built up, how folk song performers operate improvisation by changing lyrics and the way of performance, and how this improvisation finally leads to the re-creation of the tune. In order to examine the dynamic relationship between the lyrics and the tune, the computer program Praat is adopted.