When organists Carolyn Craig and Janet Yieh set out to promote the work of women composers with an Advent calendar of sacred music that lives on YouTube, they were preaching to the choirs.

Their message: It’s time to widen your repertoires.

The position of women composing music for Anglican and Episcopal church worship “could probably be paralleled to female composers in classical music in … that there are certainly [female] composers who are out there, who are very well-established, and there are persons who are less well-known,” said Yieh.

So Craig, a student at the Yale Institute of Sacred Music, and Yieh, associate organist at Trinity Church Wall Street, created a website, amplifyfemalecomposers.org, and a Facebook page.

“Part of our thinking [was] to just sort of make this music more accessible, to encourage people to expand their libraries,” Yieh said.

They first thought of putting together “a Christmas playlist,” Craig said, but ultimately chose to model their first project on an Advent calendar, which marks the days leading up to Christmas, to keep people coming back and to get more choirs involved.

The result is a daily presentation of performances from Episcopal and Anglican churches in the U.S. and U.K., as well as a few colleges, of music composed by women. Two of the participating churches are in Philadelphia. A piece recorded during an Evensong service at St. Martin-in-the-Fields Episcopal Church in Chestnut Hill will join the calendar at noon Saturday on the YouTube channel of the Amplify Female Composers’ Advent Calendar Project. On Tuesday, St. Mark’s in Center City, an Episcopal church in the Anglo-Catholic tradition, will make its premiere with a piece that was recorded for a virtual service.

In both cases, the performances being featured were already in the works when Craig and Yieh came calling.

“I learned about the project like … 10 days before it went live [on Dec. 1]. And I was really excited. And I said, ‘This is fantastic. Sign me up for a date if you need videos,’” said Lynn H. Loewi, the interim music director at St. Martin-in-the-Fields. She submitted one from a Nov. 1 Evensong service in which a soloist, Valerie Gay, and seven jazz musicians — all masked — performed Dorothy Papadakos’ “Magnificat.”

The All Saints Day service honored “voting rights activists who had died trying to secure the vote,” Loewi said.

When Robert McCormick, the organist and choirmaster at St. Mark’s, got the call a few weeks ago, he, too, had a piece in mind: Cecilia McDowall’s “Ave Maria,” which had been recorded for a recent virtual service.

“I’m more and more mindful, as many of my colleagues are, about making efforts to produce more [of the work of] women composers and composers of color,” McCormick said. “We’re realizing how underrepresented women composers have been. So I’m always on the lookout for new pieces by women composers.”

As the Advent Calendar Project counts the days until Christmas, it also reflects the year in which it’s being unveiled. The airborne nature of COVID-19 having made singing together, particularly in closed spaces, a dicey proposition, the participating groups that didn’t submit videos from pre-pandemic times employed a variety of strategies to stay safe.

Some, like St. Mark’s, used a small group of singers, masked and socially distanced. The recording, McCormick said, was made before the city’s recent tightening of COVID-19 safety restrictions. “At the moment, we can only have one soloist. Previously, we could have a small ensemble if they were a good distance from each other.”

A few other participants so far have gone the route of Trinity Church Boston, whose contribution shows its singers performing from home, coming together on their individual screens for “Drop Down, Ye Heavens, From Above” by Judith Weir. As anyone knows who’s tried to sing “Happy Birthday” over Zoom, harmony doesn’t happen without the magic of editing.

At St. Martin-in-the-Fields, the jazz Evensong had replaced what would ordinarily have been a service with a full choir — and, most likely, a full congregation. But with only 25 people allowed in the space, “when the camera pans out to the congregation, you see this, like 12 people sitting in the pews. But it was wonderful,” Loewi said.