「有一天夜在李娜家」是許常惠先生於一九六○至一九六二年間所作之鋼琴獨奏曲，這部作品的創作手法融合了東西方不同的優點，以西方的樂曲形式，加上東方的傳統語法所創作，這樣的創作手法為當時的社會環境注入了一股新的潮流，而早期的臺灣作曲界也在他的帶領之下蓬勃地發展起來，為臺灣的作曲運動寫下新的一頁。 許常惠教授（1926－2001）是作曲家、民族音樂家、教育家，在臺灣的音樂界他扮演著極為重要的領航角色。鋼琴曲「有一天夜在李娜家」，是他早期的音樂創作，本文除了對此作品詳加分析討論外，對當時臺灣的作曲環境，及其所運用之創作手法皆作深入之探討。此作品最大的意義，是其所展現作曲手法的獨創性，而獨創是藝術作品中最有價值的，此法也為後代立下了良好的典範。希望此研究結果可作為未來研究者之參考，有利日後建立臺灣作曲運動之發展史。

“One day when I was at Eilena's” was composed by professor Hsu Tsang-Houei between 1960 to 1962. This piece was blended with different styles of contemporary European and traditional Chinese music. This innovative way has influenced the trend and development of contemporary Taiwan music. Professor Hsu Tsang-Houei (1926-2001) is not only a composer, but a great ethnomusicologist and educator, who plays a very significant leadership role in Taiwan music. “One day when I was at Eilena's” is his earlier musical creation which is analyzed and discussed in this article. In the meantime, the Taiwan musical composition society and traidtional composition technique was also studied. The most valuable meaning of this work is that Hsu created an innovative composition technique. I hope the results of this study can be used as a reference for further research on the historical development in musical composition in Taiwan.