HEILIGENKREUZ, Austria - Working to reach No. 1 on the charts? Try praying.

That's how the monks of Heiligenkreuz Abbey found fame. Their compilation of Gregorian chants, a form of sung prayer, has stormed pop charts worldwide.

The debut CD, Chant: Music for Paradise, was released in Europe in May and spent 15 weeks at No. 1 on Britain's classical charts. The album made it to No. 7 on that country's pop charts.

It was also the top classical album in the United States and Canada, where it was released as Chant: Music for the Soul. It topped the pop charts in Belgium and Poland and reached No. 1 in the album charts in Austria. A special edition was recently released that includes chants sung during the Christmas season.

"I get the sense this music is able to fill a vacuum within a lot of people," said the Rev. Karl Wallner, one of the Cistercian abbey's 74 monks. "It has a basic melody that obviously speaks to people in this world who suffer from stress, aggression, lack of confidence."

As a result of the CD's success, the 875-year-old abbey, in a sleepy hamlet about a half-hour drive from the Austrian capital of Vienna, is drawing more visitors.

It was already a popular tourist attraction before the CD release, and fans are now sending e-mail saying the album helped them through hard times or changed their lives. Reservation requests at the monastery's modest guest house have shot up.

"When the monks sing, the chant opens our hearts," Abbot Gregor Henckel Donnersmarck writes in the booklet accompanying the Christmas-season album. "We hope it purifies our souls and helps us regain clarity, light, strength and peace."

Many visitors stay for the prayers. It's during these sessions - held at various times during the day starting at 5:15 a.m. - that the men, many of them young, don white robes and silently slip into church to sing the simple Latin lyrics that go back thousands of years.

That daily routine includes getting up at daybreak to follow St. Benedict's rules of ora et labora - pray and work. (The Cistercian tradition has its roots in the Rule of St. Benedict.) In the evenings, silence prevails in the abbey, which sits in the Vienna woods.

The abbey came to the attention of Universal last February, when the monks followed the suggestion of a friend who lives in London to submit their music to the company, which was searching for Gregorian singers. Within weeks, the Cistercian singers had a recording deal.

Some of the monks were concerned about how their sacred songs would be marketed. A few of the younger men worried that the media would portray them as a "boy group."

"We don't want to sell ourselves - that was important to us from the start," said Johannes Paul Chavanne, a monk at the monastery.

But Wallner said Universal was sensitive to their concerns and respectful of the religious atmosphere of the abbey during recording there.

"In the monastery, everything is uncomplicated," said Chavanne, 25, who grew up in Vienna and joined the order a little more than two years ago.

The monks have some experience being the center of attention. Pope Benedict XVI visited the abbey in September 2007, and Mother Teresa had also traveled there. In late October, former Iranian President Mohammad Khatami, who was in Austria for a conference on interreligious dialogue, also visited.

Heiligenkreuz can also claim a Hollywood connection. German filmmaker Florian Henckel von Donnersmarck, who won an Oscar for The Lives of Others (2006), is the abbot's nephew and wrote the award-winning script during a stay in the monastery.

Universal declined to disclose sales figures for the CD. The proceeds are being used to support priests-in-training who come to Heiligenkreuz from developing countries.

Hear the monks via http://go.philly.com/chant EndText