This study explores the way music operates in the mental processing of computer-supported instructional messages, whose other modes are text and graphics. The experiment examined the effect of music on the immediate recall and understanding of three equivalent science lessons delivered by a computer. The objective properties of the music were manipulated to produce feelings that were congruent with the psychological dynamics of the lessons' instructional strategies. This technique sought to enhance achievement by stimulating multiple (triple) encoding in short term memory. It aligned an abstract musical input, which elaborated subjectively on content, with instructional strategy, which is a subjective lesson element. This research, therefore, proposed and tested a variable, Music-Instructional Strategy-Integration (MISI) element, that moderated the instructional treatments. The study also sought subjects' affective evaluations of the lessons accompanied by music as well as their preferences for music in association with academic endeavors. The experimental procedure examined the effects on achievement of three forms of ninth grade lessons on physical science topics, each of which was differently moderated by music or ran in silence. The primary analysis of variance showed no significant statistical results regarding achievement. There was no statistically significant difference in the subjects' rating of the musical patterns, and no relationship between achievement scores and subjects' ratings was found. The subjects were consistent in favoring an association of music with academic activity. The study found that the inclusion of music can stimulate positive student affect toward computer-supported instruction and toward science instruction. It identifies the need for additional research with multiple encoding, and with literal music, which depicts content by becoming one of its objective parts. An appendix lists musical compositions used in the research. (Contains 69 references.) (Author/SWC)