Grooming procedures are often stressful for dogs due to exposure to loud noises, unfamiliar individuals, and the absence of their owners. This study aimed to assess whether classical music could reduce stress-related behaviours in dogs during grooming. Fifteen companion dogs of various breeds, aged 2 to 8 years, were observed during three grooming sessions: a control session without music, and two experimental sessions featuring classical piano compositions–Beethoven’s Moonlight Sonata and Chopin’s Nocturne. Music was played at 75 dB to mask ambient salon noise. Stress-related behaviours were rated on a 5-point scale during bathing, drying, clipping, and nail trimming. Results showed that all dogs, but especially males, exhibited significantly calmer behaviour in the music conditions. Female dogs showed similar trends, though differences were not statistically significant between stages. These findings suggest that classical music is a simple, effective, non-invasive enrichment method that can enhance dog welfare in grooming environments.