Jennifer Garner Says Her New Duet with Andrea Bocelli Is Now Her Son's 'Favorite Lullaby'

Jennifer Garner’s kids are her biggest fans!

The actress teamed up with Andrea Bocelli to record a new duet on the singer’s upcoming album, Si Forever: The Diamond Edition, titled “Dormi Dormi Lullaby.”

PEOPLE has a first listen at the enchanting track, which was inspired by the Chorale “Jesus bleibetmeine Freude” from J.S. Bach’s Cantata BWV 147.

“I recorded a song once years ago, so I understood the basic mechanics, but I don’t like to sing in front of anyone!” Garner, 47, tells PEOPLE exclusively. “And that seems to be getting worse as I grow older.”

Jennifer Garner and Andrea Bocelli | Steve Granitz/WireImage; Anthony Devlin/Getty I
Jennifer Garner and Andrea Bocelli | Steve Granitz/WireImage; Anthony Devlin/Getty I

RELATED: See Inside Andrea Bocelli’s ‘Elegant Yet Unpretentious’ Seaside Villa in Italy

But with producer Bob Ezrin’s support (“He was heaven,” says Garner), the entertainer was fully up to the challenge.

“He let me cover my eyes while I sang,” jokes Garner. “Mr. Bocelli had recorded his half of the duet ages ago, but he was so present for me. Hearing his voice made me feel brave. There is nothing like singing along with Andrea Bocelli.”

She also found some sweet support from her children — Violet, 13, Seraphina, 10, and Samuel, 7 — who let mom practice on them during bedtime. Says Garner: “Now my son has a new favorite lullaby!”

RELATED VIDEO: Jennifer Garner on the Parenting Moment That Gives Her Chills

While everyone is aware of Garner’s talents on the big and small screen, Bocelli says he was thrilled to discover another side of his friend through their new collaboration.

RELATED: Jennifer Garner Reveals the Surprising Compliment Fans Pay Her: ‘It Happens Every Day’

“I came to discover that aside from being a brilliant movie and television actor, among her many talents Jennifer Garner is also a very good singer,” he tells PEOPLE. “It is said that your voice is a reflection of the soul and the depth of your values is conveyed through your voice.”

Calling Peppermint star a “woman who is beautiful inside and out,” Bocelli says he was thrilled to work with “such an eclectic, curious and sensitive artist … who also had the courage to put herself out there.”

And at the end of the day, despite Garner’s initial nerves, both stars now have a beautiful memory to hold onto.

“Both of us are parents, and both of us put our heart in this song, a piece which is both an homage to Bach and a nursery rhyme, a ninna nanna,” says Bocelli. “One of those nursery rhymes that you softly whisper in your child’s ear!”