On his new album,out this week, the legendary tenor pays homage to the man he considers "the most important pope in history," the late John Paul II. But Domingo, 68, celebrates him less as a religious icon than a creative, sensitive human being: The songs on Amore Infinito ("infinite love" in Italian) were inspired by poems that the man born Karol Wojtyla wrote prior to his tenure as pope.

"I am Catholic, but this album is not for Catholics only," says Domingo, sitting in an office at the Metropolitan Opera, where he'll be honored for 40 years of service at the Met's 125th anniversary gala Sunday.

In John Paul II, Domingo saw "a personality for the whole world. He decided to dedicate himself to the church, but he could have done anything."

Domingo met with and sang for John Paul II on a number of occasions and, after performing a song based on one of his poems, expressed interest in setting others to music. He was granted access by the Vatican's publishing library and began his research about two years ago, working with his son Placido Jr., 43. "Placi," as his dad calls him, wrote several tunes for the album and translated the lyrics, which appear in English, Italian and Spanish. (The pope wrote in his native Polish.)

"Some of the first poems we looked at were based on passages from the Bible," Domingo says. For Infinito, though, he chose works he felt would have more universal resonance. La Conscienza, or The Conscience, reveals the anguish of a worker in a weapons factory, while A Mother's Wonderment and Madre reflect the love of and for a parent.

Domingo also wanted the music to be accessible to "a very broad public. It's crossover. Some songs go more in a classical direction, others are more pop, with more of a beat."

Singers who could bridge the gap were selected for a few duets: Josh Groban, Andrea Bocelli, Vanessa Williams, mezzo-soprano Katherine Jenkins and Domingo Jr., who also recorded demos for all to study, including his father. "When I heard the recordings that Placi made, I thought, 'I hope I can do it that well,' " his proud papa says.

Domingo Jr., who has a supple high-baritone voice, laughs off the compliment, but he does take credit for "choosing particular songs for the other artists. There was some controversy about who would sing what, but everyone involved was obviously honored and thrilled to do it."

For Groban, at least, Infinito succeeds in its goals. "This is not an opera album. It's not a Catholic album. It's about the human connection in all of us. Placido is a master of his craft who's never afraid to go new places."

Domingo says he's "not a fanatic" about his faith. "I think that there are things that are doubtful in the (Catholic) religion, like the fact that priests cannot be married." But he would consider a follow-up to Infinito with material based on John Paul II's more overtly religious poems.

"They're very deep, complicated but beautiful. We already have songs by Placi and other composers. That album will be more for Catholics."