There's nothing like hearing your favorite song come on the radio to liven up your spirits. Sometimes your dog may feel the urge to join in and add his own artistic take to the mix. Of course, only he knows for sure why he howls when he hears music, but the theory is that he's answering the call, engaging in some social canine behavior.
Howling in Answer
Howling is important to your dog's wild canine cousins; wolves howl to call out to the pack to bring them all together. On its own, a howl can signal loneliness, a literal cry for attention, or in a group it solidifies the group's identity. When your dog hears music, he may be hearing what he thinks is a shoutout to him and responding in kind.
Pay attention to what makes your dog howl. In an article in Modern Dog Magazine, psychologist Stanley Coren notes a study at Queen's University Belfast, United Kingdom, about the effect the type of music has on a dog's response. Heavy metal music prompted barking, compared to pop music or basic human conversation, which elicited no response. Classical music appeared to have a soothing effect, reducing barking and often encouraging them to lie down. As well, certain instruments tend to be more howl-inducing than others; wind instruments, such as saxophones and clarinets, are music to a dog's ears; a long note from a violin or a human voice also encourage a dog to sing along.