Leeds admitted he was still a little dubious. "I'd never seen a dog pant, tap a paw or wag a paw in rhythm. Would it be possible to change a dog's heart rate or brainwaves with the use of external rhythms?"

That was when Leeds hooked up with Wagner, and over the next two years they did clinical trials in animal shelters, kennels and homes.

"I was fascinated by the concept," Wagner said in a telephone chat from her home in Ohio. "I'm a veterinarian, but I'm also a musician. I've always loved music. We took four different CDs out to be tested, and the results were remarkable. I couldn't believe the differences."

The psychoacoustic music that had the most profound effect on the dogs, Leeds said, was "very slow and simple arrangements played on a single instrument, specifically the piano. We found that normal classical music was calming, but our rearranged music had twice the effect. We found that the canine nervous system reacts the same as humans to tone, rhythm and pattern."

Leeds and Wagner have written a book on their research called "Through a Dog's Ear" (Sounds True Publishing, $18.95) and have produced three CDs of music.

Their first CD, also titled "Through a Dog's Ear," features Spector on the piano with arrangements of music by Bach, Rachmaninoff, Chopin, Mozart, Beethoven and others. "The tempo is about 50 beats per minute, and it is very calming," Leeds said.

Then, he said, people came back to them and said, "'We need something to use in the car. This music calms the dogs, but it puts the driver to sleep.' We didn't want that."

"Through a Dog's Ear: The Driving Edition" was born.

It, too, features music by Chopin, Brahms, Mozart, Bach and others, but at a slightly livelier tempo and more complex patterns that work as sonic caffeine, Leeds says. It still relaxes dogs, but it engages the human brain.

They are also doing a CD like this called "For the Canine Household," for the times you might want to use the music but not get sleepy yourself.

The book and CDs are available at book stores, pet stores, on Amazon.com and at www.throughadogsear.com. If you have stories about your dogs and music, they would like you to share them on the Web site.

"Our publisher has also donated several thousand CDs that will be given to shelters, and we are also working with pilot shelters to include the CDs in adoption packages," Leeds said. "We hope they will help cut down the numbers of animals that are brought back."

As many as 90 percent of people who bring their dogs to a vet discuss some type of canine behavioral issues, the authors say. "Dog behavior problems range from mild anxiety to severe aggression," Wagner said.