The general problem of this study was to determine the effect, if any, that music had on heart rate, lap pace, and perceived exertion rate (RPE) during a 20-min self-paced run completed by a group of trained participants and a group of untrained participants. The participating subjects, all males, attended a college with an enrollment of 1,200. There were 12 participants, ranging in age from 18 to 23 years. They comprised two experimental groups. Experimental Group A consisted of 6 subjects who were considered untrained individuals, because they did not partake in exercise, or only in very limited exercise. Experimental Group B consisted of 6 subjects who were considered trained individuals, because they were in the habit of running more than three times a week to reach or exceed a target heart rate. The 12 subjects signed an informed consent form before participating in the study. No pre- or post-test capable of affecting the rate at which subjects completed the 20-min run was taken. The data were collected, condensed, and analyzed to measure performance differences when running to music and running without music. Analysis of the collected data employed Microsoft Excel as well as the t-test for the two samples’ means. Findings were that music had a noticeable effect on the pace demonstrated by both groups when running. Differences in heart rate and perceived exertion were found only in the untrained group, which may be due to source of error problems. Further research is recommended involving various styles of music and forms of athletic performance other than running.