Quantitative Analysis of Traditional Folk Songs from Shikoku District

摘要

With the objective of empirically clarifying the musical culture phenomena by which music spreads and changes, this research quantitatively analyzes the musical characteristics and regional differences of folk songs from the Shikoku district (the southern region of Japan's largest island Honshu) as case studies. All the songs from the Shikoku district listed in the quantitatively and qualitatively rich Nihon Min'yo Taikan (Anthology of Japanese Folk Songs) are digitized. We applied a scale detection method based on Seiichi Tokawa's scale theories to the same musical data and captured the characteristics of their respective schemas. In addition, an N-gram model was used to extract the trends for how interval transitions appear. We examined the frequency of each pattern for N = 1, 2, and 3, and found that in the Shikoku district, interval transition patterns that form Koizumi's four basic tetrachords as well as interval transition patterns with melodic leaps followed by progressions back to the first note in the pattern appear with a very high frequency. Additionally, we executed a classification experiment based on multivariate analysis of the tetrachords for the old Japanese provinces (ancient administrative units that were used under the ritsu ryo system before the modern prefecture system was established), and found that geographically adjacent provinces have similar characteristics. In the future, we are willing to facilitate discussion on these matters and discover the knowledge for analyzing endangered folk songs of Japan through this study.