Identification and Multivariate Analysis of 16 Compositional Elements of Relaxation—A Web-based Music Listening Study

Background Music is an effective non-pharmacologic, non-invasive, safe, and low-cost intervention to enhance psychophysiological wellness and promote relaxation. This study addresses major knowledge gaps in establishing and validating a scientifically reproducible and rigorous methodology for music repertoire selection to enhance perceived relaxation. Methods Volunteer participants (N=293) completed a web-based music-listening survey containing 16 questions on Compositional Elements of Relaxation (CER). From the unlabeled audio excerpts isolating and representing variations of each CER isolated from chronologically diverse classical music compositions spanning 400 years, respondents selected the variation perceived to be the most relaxing. Demographics including age, sex, race, education level, occupation, and level of musical training were collected. The 16 CERs identified by music experts included Accentuation, Articulation, Dynamic Range, Familiarity, Interpretive Expertise, Melodic Shape, Meter, Recording Quality, Repetition, Register, Rubato, Tempo, Texture, Timbre, Transition, and Tonality. Results The web-based music-listening survey was completed by a demographically diverse cohort of 293 volunteer participants. When choosing music with a targeted outcome of relaxation, our investigation identified, evaluated, and validated variations of 16 Compositional Elements of Relaxation that enhanced perceived relaxation. Our data showed that musical compositions with the following intrinsic characteristics promoted relaxation: lack of accentuation, legato articulation, familiarity, pp-mp dynamic range (very soft to medium soft), smooth melodic shape, quadruple meter, high clarity recording, with repetition, middle register, rubato (rhythmic flexibility), medium tempo (80-100 bpm aligning with the human resting heart rate), thin texture, piano or string instrumentation, expert performance, and smooth transition. The most significant factors associated relaxation were legato (connective articulation), an absence of accentuation (strong accents), and rubato (rhythmic flexibility inimitable by computer-generated recordings.) Results from subgroup analysis revealed age, sex, race, education, and musical training differences in preferred music for relaxation. The factors most commonly associated with differences were rubato and texture. Factors that did not differ in any subgroup analysis included Accentuation, Articulation, Interpretive Expertise, Meter, Recording Quality, Repetition, Register, and Timbre. Thin texture was increasingly preferred for relaxation with increasing education and musical training level. Conclusions Our investigation provided a reproducible theoretical framework for selecting evidence-based qualitative Compositional Elements of Relaxation (CER)—16 parameters isolated and individually assessed as correlated with perceived relaxation. This data-driven music-selecting methodology significantly increases the scientific rigor and the probability of clinical translation for music medicine research with targeted anxiolytic outcomes.