DETROIT — Madonna is on Jennifer Zablocki's iPod. So is the madonna.

The 12th-grade teacher works up a sweat not only to the pop diva's music but to songs honoring Mary, the mother of Jesus.

Among the hundreds of popular and Top 40 songs Zablocki has downloaded are songs from the Rosary Tapes, a series of Roman Catholic prayers and meditations for the rosary set to contemporary music by a pair of jingle writers better known for helping Ford Motor Co. sell cars.

"I don't make it to church every week, so it's just kind of my way of keeping in touch with my faith," said Zablocki, a 25-year-old Catholic.

The Rosary Tapes have helped open the centuries-old tradition to other Christian denominations, according to former rock station DJ Bill Gildenstern and composer John Giaier, both devout Catholics. The Michigan-based music consultants have released the fourth CD in the set and have seen more than 1 million free downloads of an earlier CD.

"It's not a Catholic prayer, it's a Christian prayer," Gildenstern said. "We all have our traditions, but the bottom line is we're Christians. I see the rosary not as something to, in any way, replace our Sunday worship together, but rather as a way to bring prayer into other areas of our lives where we may typically not pray, such as while driving or exercising."

People with few qualms about listening to something from a different denomination will have no trouble getting into the Rosary Tapes, Zablocki said.

"It's really nice-sounding music," she said. "It's not like preaching to you or anything like that. I don't think anybody would feel uncomfortable — if they weren't Catholic — listening to it."

The rosary is a series of prayers, beginning with the Apostle's Creed, Lord's Prayer, three Hail Marys and one Gloria Patri, also known as "Glory Be To the Father." Catholics believe that as the rosary is recited, a person is able to see Jesus through Mary. A string of small rosary beads typically is used to count prayers.

Jesus' birth, baptism, crucifixion and resurrection are part of the 20 mysteries that make up the Joyful, Sorrowful, Glorious and Luminous mysteries in the rosary.

Gildenstern and Giaier, who helped compose "Have You Driven A Ford — Lately?" and have written thousands of other advertising jingles in a more than 30-year collaboration, added original lyrics, music, percussion, acoustic and electric guitars, organs, pianos and vocal harmony to the devotional prayers.

"The mix with contemporary music is rather unique, and I think it's an attraction to the style of prayer for a number of people," said the Rev. Bob Konopa, a priest at Saint Thomas Aquinas Church in Saginaw, Mich.

"We've used them in the church during reconciliation services for children. The response has been good."

Gildenstern said he was motivated to create the Rosary Tapes to help him recite the prayers while driving, but Giaier said he had to be sold on the project.

"I was selfishly thinking of how it would look in our industry as being religious fanatics," Giaier said. "I thought he was out of his mind. I wanted no part of it."

But Gildenstern took one of the mysteries, tapped out "Silent Night" on the piano and had his wife sing the Christmas hymn while the rosary was recited.

The combination brought Giaier's wife to tears. "From that moment on I've felt drawn to do this," he said.

"Joyful Mysteries" was released in 1992, and the "Sorrowful" and "Glorious" mysteries a year later. Free Internet downloads of the "Joyful Mysteries" started in 2001, and the "Mysteries of Light," or "Luminous Mysteries," was released this winter.

In addition to the free Internet downloads of the "Joyful Mysteries," more than 40,000 sets of the Rosary Tapes have been sold, far from enough to make the two longtime friends wealthy.

The four-CD set costs $39.95 online.

The tapes have renewed Cleo LaVoie's enjoyment of the rosary.

"For a while, the rosary just went away," said the 82-year-old, who lives near Duluth, Minn. "When you say the rosary at church, it's kind of dry.

"I love the tapes," said LaVoie. "The music kind of inspires you."