University students (N = 30) individually listened to the Billboard 100 top-ranked musical selection for their most and least liked musical genre. Two minutes of silence preceded each musical listening condition, and heart rate variability (HRV) was recorded throughout. All HRV measures decreased during music listening as compared with silence. Dependent t-tests found significant decreases for beats per minute (p less than 0.01, like; p less than 0.001, dislike) and low frequency (p less than 0.01, like; p less than 0.05, dislike). A significant decrease in low-frequency/high-frequency ratio (p less than 0.05) was found for the dislike-music listening condition. A sign test showed no significant difference in the number of mean readings that increased or decreased for either music listening condition. Findings may support previous research that HRV decreases during mentally engaging tasks but may not support previous research that HRV readings could be a measure of emotional responding. (Contains 2 tables.)