By careful consideration of the origins of a breed, it is often possible to come to some logical conclusions behind behaviors that seem to make little sense to us. Of course, everything Fido does always make perfect sense to him. The lesson we can learn from this is that most canine behaviors are firmly rooted in logic. If your Border Terrier likes to sing, there is likely a good reason why. Does your Border Terrier just like to make a lot of racket? Is he seeking attention from you? Fido's lips are firmly sealed on the matter. He knows the answer, but he's not going to tell.
The Root of the Behavior
Communication would form a critical part of the relationship between the Border Terrier and his owner, the hunter. Once a Border Terrier had located the prey, it would be necessary for him to alert the hunter to inform him that he had the prey cornered and was about to drive it from its earthly tunnel to above the ground. The Border Terrier would accomplish this through his own unique sound that to some is reminscent of singing. Others would describe it as more of a howl or even a unique barking or baying sound. Some Border Terrier owners liken the "singing" to the baying of a Beagle out on a hunt. Beagles were also dogs used in the hunting of rabbits, and though they did not go to ground, they were responsible for alerting their owners to the presence of the desired prey and did so via baying. As with many breeds bred for a specific purpose, hunting is immensely satisfying for the Border Terrier. Today's Border Terriers, though largely placed in pet homes and no longer used for hunting, still possess the drive to do the work they were originally bred to do. Because of this, they are still hallmarked by prey drive which can be evidenced by stalking and chasing behaviors toward small animals including rodents, rabbits, and even cats.
Encouraging the Behavior
Though the piercing sound of the Border Terrier's singing would undoubtedly carry some distance over fields and forest, it would be difficult to determine how near the hunter was to the dog and his cornered prey. This is why hunters most often worked alongside packs of dogs instead of merely taking one. The other dogs would join in the "kill cry" to help the sound to penetrate to where the owner was and provide an aural trail of where to reach the dog and his quarry. It is important to understand that a Terrier who took it upon himself to kill the prey was considered a liability to the hunter. The Border Terrier's job was simply to inform the hunter of the location of the prey. Once the hunter arrived on the scene, the dog's function was to drive the prey above ground. Dogs who went in for the kill themselves were often culled by their owners. In the early days of the breed, dogs were rarely kept as companion animals. Food was harder to come by, and hunters could not afford to feed and keep an animal that did not properly do its job. Sadly, there was little sentimentality towards the life of animals as what we see today.
Other Solutions and Considerations
Many dog owners cite their dogs howling along to their favorite Katy Perry song. Is it because they love it and want to join in? Do the tones of the particular song hurt their ears in some way? Maybe Fido just really hates Katy Perry; it's hard to say. But we do know for certain, that sometimes our dogs do erupt into spontaneous song, and we love it. It is highly entertaining and never fails to bring a smile to our faces. If your Border Terrier's singing is an annoyance to you, the best thing that you can do to reduce it is to remove access to things which elicit the reaction. If Fido spends a good portion of his day staring out your living room window then alerting you to every tumbleweed that floats by, it is best to remove the portion of furniture he stands on that provides him the vantage point for his daily observations. You may not be able to completely eliminate this well-ingrained behaviour, but you can reduce and discourage it, and your neighbors will likely thank you for it.