Qualitative and quantitative features of music reported to support peak mystical experiences during psychedelic therapy sessions

Psychedelic drugs such as psilocybin can occasion profound alterations in perception and consciousness, including mystical or non-dual experiences characterised by a sense of oneness, positive mood, and difficulty verbalising the experience. Earlier research and recent clinical trials have suggested therapeutic potential for psychedelics in mood disorders and addiction, and mystical-type experiences have been linked to therapeutic benefit. Music is commonly used during psychedelic sessions because it is believed to provide psychological support and to facilitate such peak experiences, but the specific musical features that are supportive across different phases of the drug effect have not been well quantified or standardised. Slevc and colleagues set out to identify and characterise the musical features that experienced psilocybin guides report as supportive of mystical peak experiences and of the period leading up to a peak (‘‘pre-peak’’). The investigators conducted an anonymous online survey of therapists and guides with extensive psilocybin-guiding experience, then applied both qualitative expert ratings and quantitative Music Information Retrieval (MIR) analyses to the recommended musical selections. The aim was to generate an empirically grounded description of music that may be optimal for supporting peak psychedelic experiences and to provide a foundation for future standardisation and experimental testing.

The study used an anonymous online survey targeted to expert psilocybin guides, defined as individuals who had guided more than 50 people in high-dose psilocybin sessions that included music listening. Respondents provided minimal demographics, described typical session characteristics (posture, use of eyeshades, indoor/outdoor setting, presence of a co-guide, frequency and duration of music use, and session goals), and listed two to three musical pieces they considered optimally supportive for peak mystical/non-dual experiences and two to three pieces supportive during the period leading up to a peak (pre-peak). Mystical or non-dual experiences were defined for respondents in terms consistent with prior research (profound oneness or unity). Qualitative analysis began with three authors experienced in music theory and music cognition who reviewed the submitted selections and developed a consensus list of musical and acoustic features to rate. Two experts then listened to each submitted recording and rated the consensus features; the feature list was iteratively refined to those prominently expressed in peak or pre-peak selections and finalised by consensus among the three raters. Quantitative analysis applied Music Information Retrieval (MIR) methods to the audio recordings. Extracted MIR features included timbral measures (zero-crossing rate, high/low energy ratio, spectral centroid, spectral entropy, spectral rolloff, spectral flatness, total and sub-band spectral flux, roughness), tonal features (key, key clarity, mode), temporal features (pulse clarity, event density), and RMS energy. Time-course extraction used frame sizes appropriate to each feature (for example, key/key clarity/mode at 1 s with 50% overlap; pulse clarity at 5 s with 10% overlap; event density at 10 s with no overlap; other features at 50 ms with 50% overlap), and mean values over each selection were used as inputs. Principal components analysis with varimax rotation was performed on the averaged MIR features to derive components corresponding to perceptual dimensions (labelled by inspection as Brightness, Activity, and Fullness among others); the first nine components explaining 94% of variance were retained. Component scores for each stimulus were compared between peak and pre-peak sets using Welch's two-sample t-tests. The analytic pipeline resulted in parallel qualitative and quantitative descriptions for musical stimuli recommended by respondents. The extracted text does not provide full details of the survey recruitment pool beyond word-of-mouth invitations, nor does it report whether any procedures were used to verify independence of respondents' training or prior influences.

Ten respondents met the inclusion criterion (guiding at least 50 people) and completed the survey; three were female. Respondents reported extensive guiding experience (mean individual high-dose psilocybin sessions guided M = 365, range = 60 to 2,000; mean number of different people guided M = 213, range = 50 to 1,200). Seven participants reported guiding group sessions (mean = 106 group sessions, range = 5 to 400). Typical session conditions reported were high rates of music use (six guides used music in 100% of sessions; others reported near-ubiquitous use), volunteers usually lying down, frequent use of eyeshades (nine respondents), indoor settings, and common goals that included healing, insight, spiritual growth, and mystical experience. Respondents initially submitted 27 unique recommendations for peak music and 27 for pre-peak music. Three items that were recommended for both periods were excluded for non-specificity, and four recordings were unavailable to the investigators; the final analysed corpus comprised 22 peak stimuli and 22 pre-peak stimuli. Qualitative ratings were produced by two expert raters following an initial consensus process among three authors. Qualitative analysis found consistent characteristics that differentiated peak from pre-peak music. Peak-period music was described as having regular, often breath-length phrase structure, simple (often quadruple) metre, steady metric pulse, and melodic, harmonic, and instrumental material that remain relatively constant across a piece. Many peak selections were ensemble textures that obscure identification of individual instruments; when solo instruments were featured, they were often non-European. Peak music conveyed a continuous sense of forward motion or slowly building directed movement and was generally consistent and predictable rather than changeable or jarring. By contrast, pre-peak music lacked common, salient qualitative features across selections; within many pre-peak pieces the opening minutes were not predictive of later material, and there was less sense of large-scale directed motion. Quantitative MIR analysis produced principal components that mapped onto perceptual dimensions labelled Brightness (component 1), Activity (component 2), and Fullness (component 3), along with components for mode, key, pulse clarity, and event density. Statistical comparison between peak and pre-peak stimuli identified a single quantitative dimension that reliably differed: peak-period music had relatively lower perceptual Brightness and possibly greater Fullness compared with pre-peak music. The investigators did not find convergence on other features: for example, tempo emerged in qualitative ratings as distinguishing peak and pre-peak music but did not differ significantly in the quantitative measures. The small sample of stimuli and respondents is reported as limiting statistical power and the ability of quantitative methods to capture certain compositional features.

Slevc and colleagues interpret their findings as identifying clear differences between music recommended for peak psilocybin periods and music recommended for the pre-peak phase. The most striking result was consistency among peak-period selections: expert raters converged on features such as predictable phrase structure, simple metre, steady pulse, homogeneous instrumentation, and a sense of continuous, slowly building motion. The researchers argue that such characteristics are intuitively plausible for supporting experiences of unity or diminished self-boundaries because unpredictability, abrupt transitions, or strong variation could provoke vigilance or distraction contrary to a mystical state. Quantitatively, lower perceptual Brightness in peak music emerged as the primary MIR-derived distinguishing feature, with a possible increase in Fullness. The authors emphasise that the quantitative and qualitative approaches were complementary but did not fully converge; tempo, for instance, was highlighted qualitatively but did not differ in the MIR-derived metrics. They suggest that expert human raters may be sensitive to compositional qualities that automated analysis struggles to capture, particularly orchestration and polyphonic texture. The investigators propose a conceptual model in which music exhibiting the identified peak-period characteristics may facilitate mystical peak experiences during psychedelic therapy. They outline future empirical tests: (1) selecting existing music that matches or does not match these characteristics and testing effects on subjective measures such as the Mystical Experience Questionnaire (MEQ30) and long-term outcomes, and (2) composing novel music that embodies or intentionally omits these features to test causality. The authors note the potential value of novel composed music to avoid idiosyncratic personal associations that listeners bring to familiar music, which could otherwise introduce uncontrolled variance. Key limitations acknowledged by the study team include the small sample size (10 respondents and 44 stimuli), the anonymous recruitment method that precludes full verification of respondents' independence or training, and possible respondent bias rooted in shared traditions or personal preferences. The authors also recognise methodological limits of MIR: automated analyses can quantify many acoustic attributes but remain challenged by aspects such as orchestration in polyphonic music. Finally, the investigators caution that their findings are specific to psilocybin contexts and require testing to determine generalisability to other psychedelics and to confirm that these musical features causally influence mystical experience.

This exploratory study provides an initial, empirically grounded description of musical features that experienced psilocybin guides report as supportive of peak mystical experiences. Music recommended for peak periods was characterised by regular, predictable phrase structure and orchestration, a continuous sense of forward motion that slowly builds, and lower perceptual brightness compared with pre-peak music. The authors present these findings as a tentative first step toward standardising and optimising music selection for psychedelic therapy, while emphasising the need for experimental validation, larger-scale quantitative analyses, and evaluation of generalisability to other psychedelic drugs.