On her security camera, Strull saw the impact on Margot almost immediately. She says she used to receive texts from her neighbours complaining about Margot barking when she was left alone. Now, rather than pacing and barking, Margot peacefully naps, with Brahms or Beethoven on in the background, while her owner is gone. “There have been times where I haven’t gotten home till 4am, and she’s just asleep.”

Other studies have come to similar conclusions. One from Queens University Belfast looked at the impact of three types of sound on kennel dogs and dogs in private homes: classical music, audiobooks and silence (the control group). After closely observing behaviour changes, the researchers concluded that classical music had a notable calming effect in “acutely stressful situations”, such as a visit to the vet and a long car ride.

Not all styles of classical music are effective, though. Slow tempo (50-60 beats per minute or less), simple compositions with low or no percussive elements are best. That combination has been shown to reduce cortisol levels (the hormone that indicates a stress response) in dogs; however, the underlying reason for this effect is less well understood.

“The most sensible explanation is that there is something inherently relaxing about this genre of music, perhaps resulting in the release of chemicals that bring about a pleasurable state of mind,” says Deborah Wells, co-author of the study and an animal behaviour researcher at Queen’s University Belfast. 

Wells has studied the effects of classical music on a range of species, including those found at zoos, such as elephants and gorillas. “Zoo-housed elephants and gorillas showed welfare advantages, spending less of their time engaged in stereotypic behaviour, and/or aggression,” Wells says. Other welfare advantages can include better eating and sleeping habits, stronger immune systems and improved fertility.