A funny thing happened to Ari Y. Kelman on the way to co-authoring the 2010 book “Sacred Strategies: Transforming Synagogues from Functional to Visionary.”

The Jim Joseph Chair in Education and Jewish Studies at the Stanford Graduate School of Education, Kelman found himself taking notes and singing worship songs in evangelical churches.

“I was going around to synagogues to learn what made [them] so great,” he said, alluding to the book’s focal point: eight congregations that went above and beyond in helping people connect to Judaism in new ways. “Often, they said I should come to Saturday services, come to shul ‘because the music is amazing.’ I would go. I would frequently leave thinking that it wasn’t so amazing. They sang the same melodies that I sang as a kid.”

At the same time, Kelman began sidetracking to hear music he actually did find “quite moving.” And that happened to be mainly in white Christian churches. “I started wondering, ‘Who is thinking hard about … how to leverage whatever is in music to create powerful experiences?’ That eventually led me to church.”

Kelman chronicles his research detour — which included interviews with 75 evangelical songwriters, worship leaders and music industry executives — in the newly released “Shout to the Lord: Making Worship Music in Evangelical America.”

In his findings, Kelman, a scholar of Yiddish radio who has experience leading Jewish worship, sees several lessons for Jewish devotion and synagogue culture — topics he doesn’t address in his book.

Across the nation in white evangelical churches, large and small, Kelman encountered an earnestly composed, intentionally understated, frequently updated canon of worship music that is the primary mode of prayer for tens of millions of worshippers.

The longtime Jewish studies professor and researcher describes the popular-style songs as “ritual forms … that can instruct people in worship, enable them to worship and help them to cultivate their own relationship with the Divine.”

For the past 25 years, most of those songs have been written in a rock ’n’ roll style; thus, most evangelical church services these days are accompanied by an amplified rock band. Kelman describes a typical evangelical service as lasting 60 to 90 minutes, with 30 to 35 minutes of worship singing, plus a sermon and announcements.

“There isn’t a prayerbook,” Kelman explained. “They project song lyrics on screens.”

The songs are meant to strike a balance between being musical enough to be inspirational, yet not so artful as to be difficult to sing or distract the congregation from the songs’ purpose: effecting a connection to God.

The songwriters “attend to their lyrics with great care,” Kelman writes, seeking “to express eternals truths in novel ways” within a format “constrained by a limited range of possible subjects,” primarily stories about Jesus and praise for God.

The worship leaders, many of them songwriters, believe that “one has to worship” — both in general and during a given service — “in order to lead worship,” Kelman writes.

There isn’t a prayerbook. They project song lyrics on screens.

This scrupulousness to principle extends throughout the industry to the specialized music publishers and recording companies. “You think the music is just what happens when you get to church,” Kelman said. “It actually is this very complicated assemblage of forces and people and objects that make it possible.”

In other words, it takes a culture to raise the proverbial roof with a worship song.

White evangelical worship music first shifted from traditional hymns in the 1960s, when young worshippers — like some of their Jewish contemporaries — sought to pray in their own musical vernacular inspired by the secular folk music they heard singer-songwriters performing.

But the parallels stop there. Kelman pointed out that the evangelical musical approach wouldn’t work in many synagogues, which forbid the use of instruments on Shabbat and holidays.

Moreover, Jewish prayer has “a fidelity to a liturgical tradition that you don’t have in the evangelical community,” he said. “Jews typically pray out of a siddur [prayerbook] … On top of that, the singing parts are probably 2 or 2½ hours of a 3-hour service, because you have a lot more ground to cover in a Jewish service.”

The drive for new music also is less pronounced in Judaism, Kelman noted, as many of the cantors who lead Jewish singing “are not composers or trying to be composers of new music.”

And while evangelicals seek a “direct connection to God” in worship, Kelman said, most members of liberal U.S. Jewish congregations don’t believe in the God of the Bible, according to recent studies, and attend synagogue “for different reasons.”

Still, Kelman said congregations and institutions should follow evangelicals’ example of scrupulously paying songwriters for the rights to use their songs.

Ane as for evangelicals’ commitment to innovation, “there’s a lot we can learn from that,” Kelman said. “It’s probably worth having a conversation about the purpose of Jewish prayer and what people think they’re doing with it.”

He also alluded to “a broader conversation that could be happening and thinking differently about fidelity to tradition.” For more on that, see that other book he was working on in 2010.