Couple's piano duet a YouTube smash

ROCHESTER, Minn. (CNN/KARE) - When an impromptu performance in the Mayo Clinic's atrium was uploaded to YouTube, it touched a chord in millions of people.

The stars of the video? Marlow and Frances Cowan, a charming couple from Iowa who simply played the piano in between doctor appointments to entertain themselves.

"I saw that piano and it said 'if you'd like to play it' and I touched the key and I thought, WOW, now THAT's a piano," said Marlow.

The Cowans had five days of appointments at Mayo, when meant they had plenty of downtime and plenty of time to play. On their last day, another patient recorded the show.

6.5 million plays on YouTube later, the Cowans returned to Mayo for an encore performance last week.

"We're glad to be anywhere at our age," said Marlow.

The Cowans say they've been entertainers for a long time, performing at nursing homes, hospitals, and even prisons "if they want us." But they don't own a computer, so high-tech forms of entertainment like YouTube leave them a bit baffled.

They believe a little help from above made their clip so popular. The Cowans have a deep faith and say they ask God the same question every night: "Lord, what can we do to glorify you in our old age?"

On their return to Mayo, the Cowans had a message for their audience: "Keep singing and God Bless you all."