The last time the Portland String Quartet performed in front of a live audience was November 2019, before the pandemic. Julia Adams, the founding violist, was still a member of the venerable ensemble.

Adams, who lives in Portland, has since retired, and the quartet will continue forward with one original member, violinist Ronald Lantz. With a guest violist in place, the Portland String Quartet performs its first concert with a live audience since the pandemic began at 2 p.m. Sunday at the newly opened Portland Conservatory of Music at 28 Neal St. in Portland’s West End. The program will include music by Franz Joseph Haydn, Florence Price and Bedřich Smetana.

Dean Stein, who plays violin in the quartet, called it “happy circumstance” that the quartet is beginning anew in a conservatory’s new space. The conservatory will christen Portland’s newest performance space, a former sanctuary, with a Dimensions in Jazz concert at 7:30 p.m. Saturday, and the PSQ will be the first classical concert the following afternoon.

“It’s a jewel of a place to perform in, a very intimate venue. We’re delighted we can help the Portland Conservatory celebrate the opening of its new location and at the same time enjoy being back live again,” Stein said.

In addition to Lantz and Stein, the quartet includes cellist Andrew Mark. It continues its search for a replacement for Adams, who played with the quartet for 51 years. On Sunday, violist Matt Consul will perform. He played with the quartet in some of its online concerts earlier in the pandemic. “He is a beautiful player, and we have invited him to play live with us,” Stein said, noting that a search for Adams’ replacement will continue in November with a guest appearance by violist Brianna Fischler. “It has to take the time it takes. It has to be the right person,” he said.

Returning to performance with live audiences with a Haydn piece is appropriate, because Haydn created the string quartet art form. Price was a Black composer, whose music the PSQ has performed before and will again. The Portland Symphony Orchestra also will perform her music in the upcoming season. She wrote her Quartet in G Major, on tap for the PSQ, in 1929 in the romantic style. Finally, the Smetana piece includes what Stein describes as “a huge viola solo at the opening that will provide Matt (Consul) a beautiful opportunity to sing out.”

For the opening concert, the members of the quartet will perform wearing masks and will require audience member to wear masks, as well.

“We can do it. We are not wind players, so why wouldn’t we,” Stein said. “Is it ideal? No. Let’s do it anyway.”