Abstract Background Heart rate variability (HRV) is indicative of autonomic balance. High HRV during sinus rhythm is associated with reduced morbidity and mortality across a wide range of health disorders. Listening to music has been shown to induce psychological and physiological responses that increase HRV, a mechanism currently employed in music therapy to reduce anxiety and post-operative pain. However, it remains unclear which music characteristics have the most positive effect on HRV. Purpose This study aimed to assess the impact of different music genres, white noise, tempo, and personal music preferences on HRV. Methods Adults without atrial fibrillation or pacemaker dependency were included during the Netherlands largest three-day music festival. Participants were subjected to three-minute fragments of white noise, and subsequently a randomized order of classical, rock, electronic and the subject’s most-listened personal ("Spotify Wrapped 2022") music; all having an either fast (130-140 BPM) or slow tempo (70-80 BPM), which was randomized as well. Afterwards, participants ranked all music fragments in order of their preference. A tachogram was collected using the PPG sensor of an Apple Watch Series 8. Data was pre-processed to exclude non-sinus rhythm beats and measurement artefacts. HRV time-domain (SDNN, RMSSD, NN50, pNN50, triangular index) and frequency-domain (LF, LFn, HF, HFn, LF/HF) metrics were calculated from the tachograms using Python-software. HRV outcomes were corrected for age, sex, heart rate and music tempo group and analyzed using general linear mixed models in SPSS. Results In total 242 participants with a median age of 28 years (IQR 24-32) were included, of which 136 (56%) female. Classical music showed a significantly higher HRV response (RMSSD) compared to electronic (p=0.025) and the subject’s personal music (p=0.030, see figure). No other significant differences in HRV were found between the different genres and personal music. White noise showed a significantly higher HRV for all time domains, as well as LF and HF, compared to the different genres and personal music. A total of 181 (74.8%) participants ranked their personal music fragment as the most preferred. There was no difference between the fast and slow tempo group when performing an interaction analysis for tempo and the different music genres except for classical and personal music (RMSSD, p = 0.047). Conclusions This large study highlights that classical music enhances HRV more than other music, suggesting its therapeutic potential. Remarkably, white noise showed the greatest increase in HRV. Although these were bitter pills to swallow; white noise or classical music once a day might keep the doctor away.