Combine one part soulful Carlebach service with one part large Reform synagogue. Add one dash U.S. Army chaplain and one pinch singer-songwriter Craig Taubman. Shake thoroughly. Serve in San Francisco’s most beautiful synagogue sanctuary.

Voila! The result of this unexpected recipe is Cantor David Frommer’s secret Carlebach service at Congregation Sherith Israel, one of San Francisco’s venerable seats of Reform. I don’t know what I was expecting, but the June installment of this monthly (but unpublicized … until now) service was a warm, uplifting and altogether pleasant surprise.

This is Frommer’s pet project, born out of his longing for the services he enjoyed in college and when studying in Israel. When he first came to San Francisco, he worked only part time, and could get some of that at Mission Minyan.

But when he started working full time, he wasn’t able to get out on Friday nights to try other services around town. (I hear similar regrets from many Jewish clergy who wish they had more time to explore and check out the competition.)

Mission Minyan also inspired him to try something out: Could his congregants take to that style of prayer? “I want to see what that would be like in practice in my community … It was curiosity about how my community would take to an all-Hebrew service,” he told me.

Here Frommer brings up an assumption many Reform clergy make: that more Hebrew will freak out their congregants. That may or may not be true, but it’s a familiar line of thinking among Reform synagogue leaders. To his credit, Frommer is putting that assumption to the test.

So far, the service at Sherith Israel is monthly. The week I went, there were exactly 10 people, all under 40; several had come as couples. Frommer said that over the course of the few months of this service so far, about 40 people have come, and almost all have returned or expressed interest in doing so.

The music (almost) entirely consisted of music by Shlomo Carlebach, the famed 20^th-century Jewish singer and composer who made a massive impact on Jewish liturgical music worldwide, and famously ministered to youth in Haight-Ashbury at the height of the counterculture movement.

Frommer’s fears about people knowing the music turned out to be only somewhat warranted. Not everyone knew every single tune, but there was a critical mass (well, a handful of the 10, anyway) singing along with each one. Carlebach’s music is full of yearning and joy and overflowing with nigguns — especially the Friday night Carlebach canon that has developed over the years. If just a few people in the room know the melodies, the rest comes together on its own.

That said, it turns out that there is a glaring gap (according to Frommer) in Carlebach’s oeuvre: Hashkiveinu, a prayer for safety and protection during the darkness of nighttime. In most Carlebach-heavy settings, it’s a non-issue because it is most often read silently. But the Reform movement loves to sing Hashkiveinu. Cue the flashbacks to my youth at Reform summer camps. In the throes of the compulsion toward singing Hashkiveinu that I can only assume is beaten into Hebrew Union College cantorial students during their first semester, Frommer paused the service to note that Carlebach had failed us in this area.

And that is how we came to sing Craig Taubman’s Hashkiveinu in the middle of an otherwise wall-to-wall Carlebach service, a truly rare juxtaposition. Taubman is one of the most well-known exemplars of Reform folk guitar liturgical music, so it’s not exactly novel to hear in a place like Sherith Israel. But in an otherwise all-Carlebach service? As novel as it gets.

Frommer, as it so happens, is also a chaplain with the U.S. Army National Guard. So, naturally, we used the 2014 “Prayer Book for Jewish Personnel in the Armed Forces of the United States.” The pocket-size, camo-covered siddur is fascinating; I was delighted to get a chance to play with one. I could write a whole column about this siddur, but I’ll just say that you should Google it if you’re into these things.

The dome is a visible piece of the skyline in a good chunk of the city, and it has survived more than one catastrophic earthquake — but from the inside it seems to float lightly overhead. The Beaux Arts/Byzantine/Romanesque structure was not oppressive or heavy in the way that grand sanctuaries often are. Seated as we were directly below, it encouraged us to soar.

It’s funny — put 50 Reform congregants in a space this size, and it’s like pulling teeth to get them to sing. They’ll scatter themselves around the room, creating a feeling of emptiness even if quite a few are present. We had just 10, yet we filled the cavernous space with sound.

Above us was some of my all-time favorite synagogue stained glass: an image of Moses, returned from Sinai with the two tablets. But in this version, Sinai is replaced by Half Dome and El Capitan, the iconic mounts of Yosemite. It is the purest statement of classical West Coast Reform: Welcome to California, the goldene medina, the only Promised Land you need.

The entire experience of the “secret” Carlebach service was an almost preposterous pendulum swing of history, I thought, struck with a vision of Sherith Israel’s framers. What would those Reform Jews of yore have said if they walked in on this 2017 service? The people who conceived of and funded that stained glass also funded a monumental organ and one of those classic hidden choir lofts. Are they spinning in their graves at the sound of so much Hasidic-flavored niggun-ing in their great Temple? Or are they smiling down, content to listen as Jewish music marches on without them?

So why keep this gem of a service secret? The answer is simple: “It’s secret because I don’t know what to call it,” Frommer said.

“I didn’t want to put it up on the website of my Reform synagogue; it’s not helpful to say ‘Carlebach’ to Reform Jews. So I wanted to build it with people who I knew were open to it or searching for it.”

That’s a bad reason to not call it a Carlebach minyan. Growing up Reform, we were often treated with kid gloves, as if any unfamiliar term would scare us away. But if you’re going to learn new things — as Jewish a pursuit as I can think of — you’re going to have to be OK with new words.

That said, I can think of one very good reason not to call attention to the Carlebach name. Though he appeared to be, in many ways, a groundbreaking feminist — he was the only male rabbi present at the first meeting of Women of the Wall in the late 1980s — Carlebach has also become known, in the years following his death in 1994, for sexual abuse. In response, many progressive Jews have attempted to excise his music or diminish its role in their prayer.

I don’t have any interest in tossing his many musical achievements out the window. But, following the lead of many Jewish women I trust, I do not believe his name should be glorified either. In the ’90s, so-called Carlebach services proliferated. There is even a Carlebach synagogue in Manhattan. But I believe it is no longer appropriate to glorify his memory in this manner.

For now, Frommer said, the name of the service varies depending on the audience. “Some say I shouldn’t call it [a Carlebach service] because they’re not comfortable with him as a person. Then again, if I’m telling someone about it and I know they like Carlebach, it’s called a Carlebach minyan.”

Frommer and Sherith Israel really have something here. I hope he can settle on a good name and find it within himself to start publicizing it. There is so much promise in this service; it would be a great addition to my list of exciting Friday night options in San Francisco.

And hey! If you don’t know where to go to shul this Friday, fear not: the Carelbach-with-a-dash-of-Taubman minyan rides again this week. 7:30 p.m. Friday, July 28 in the main sanctuary at Congregation Sherith Israel, with dinner somewhere on Fillmore after.