The aim of the study was to evaluate the effect of music therapy on changes in the level of parameters describing heart rate (HR) and heart rate variability (HRV) as excitability indicators in geriatric horses. The study involved 20 warmblood geriatric horses, aged 20 years or more. Animals were kept in two identical stables in one facility. Horses from stable No. 1 were considered the experimental group, whereas horses from stable No. 2 constituted a control group. The experiment consisted in playing relaxation new age music to the horses in the experimental group for 28 days use special sound system (MyPetSpeaker). To examine the emotional excitability of horses from both groups, HR and HRV parameters were used. The subsequent measurements were performed morning at rest at 7-day intervals, counting from the first day of the experiment, and four measurements were recorded. HR and HRV measures indicated that daily exposure for several hours to new age music had a positive effect on relaxation of geriatric horses. A short-term effect of 1-2 weeks duration was observed beginning 1 week after onset. Unfortunately, the effect disappears after subsequent 2-3 weeks of therapy application, without leaving spectacular results.