This study is aimed to develop the interdisciplinary SoSTI (science of sound in traditional Thai musical instruments) course for Thai non-science upper secondary school students to study the students' attitudes toward science before and after studying from the course. The SoSTI course development is based on the interdisciplinary concept model and constructivist theory. The research study is divided into five phases: (1) pre-developing the course, (2) developing the course, (3) conducting the pilot study, (4) implementing and evaluating, and (5) analyzing data and writing the conclusion, respectively. The SoSTI course is an elective course corresponding to the Basic Education Core Curriculum B.E. 2551 (A.D. 2008). This course was conducted with 35 12th-grade non-science students in the second semester of the 2010 academic year at a school in Bangkok, Thailand, for a whole semester. The research instruments were students' attitude toward science questionnaire, and students' opinions toward the SoSTI course questionnaire. The results of this study presented that, after completing the SoSTI course, the students' attitudes toward science comparing before and after studying the SoSTI course were not significantly different at the 0.05 level. However, they have positive opinions toward the course. [This work was financially supported by the Institute for Promotion of Teaching Science and Technology (IPST), Bangkok, Thailand.] (Contains 3 tables and 2 figures.)