The month-long celebration of Christmas continues in full force this week.

Tops in my opinion is the annual Christmas at the Cathedral, a wonderfully spirited and spiritual concert that will be presented four times Dec. 5-6 in Portland by the Choral Art Society plus invited guest artists.

Another fine concert, much in the same vein, but way smaller in scope, is Saint Mary Schola’s annual Advent concerts. Three performances are scheduled over a six-day span; the first is in Brunswick on Dec. 8.

“Broadway at Good Theater,” which runs through Sunday in Portland, is a tribute to the 1930s and all of the amazing musicals that opened on the Great White Way during that decade.

Portland String Quartet presents the third concert of its 2015-2016 season Dec. 6. On the program will be works by Franz Joseph Haydn, Ernest Bloch and Ludwig van Beethoven.

Christmas at the Cathedral

Last week I mentioned that Robert Russell has retired as professor of music at the University of Southern Maine, where he directed the choral arts program for 35 years. But Russell has most definitely not retired as the artistic director of the Choral Art Society, which is a totally independent vocal ensemble that he has also helmed during those 35 years.

Christmas at the Cathedral is CAS’ biggest annual event, and for the past 28 years Russell has shaped its program to embrace a wide diversity of musical styles, anchored by traditional music but including contemporary treatments in keeping with the spirit.

I attend about a dozen Christmas concerts every season, and this is definitely my favorite. The setting – one of Maine’s largest and most magnificent churches – and the music have an absolutely magical effect on me.

Two pieces are performed every year. “Personent hodie voces puerulae” is a Latin hymn dating from the late 1500s in Finland. Arranged for chorus by Russell, it’s the CAS’ signature work. The second, also a signature showcase, is “Silent Night,” which is performed with the singers lined up on both sides of the cavernous cathedral, holding candles.

Other works on Russell’s program were penned by well-known composers such as Michael Pretorius, Felix Mendelssohn and Gustav Holst. Several popular Christmas carols are performed as well as a number of medieval Latin hymns.

Joining the singers will be organist Dan Moore at the keyboard of the cathedral’s mighty instrument and the Portland Brass Quintet, which mostly comprises members of the Portland Symphony Orchestra.

Christmas at the Cathedral will be performed Dec. 5 at noon and 8 p.m., and Dec. 6 at 2:30 p.m. and 7:30 p.m. at the Cathedral of the Immaculate Conception, 307 Congress St., Portland. Call 828-0043.

Saint Mary Schola

Another wonderful feature of the Christmas season is Saint Mary Schola’s annual Advent concerts, usually given three times, in Brunswick, Portland and Falmouth.

Saint Mary Schola is a Falmouth-based ensemble of about 10 professional singers and instrumentalists who specialize in early repertoire – roughly defined as music of the Renaissance through mid-1700s. Artistic director and conductor is Bruce Fithian, a recognized performer-scholar who teaches at several Maine colleges.

Saint Mary Schola’s Advent concerts mix music with spiritual readings. This year’s title is “Today’s Light,” with Johann Sebastian Bach and William Byrd as the best-known composers represented. Among poets and authors on the program, John Milton and Richard Wilbur have the widest reputations.

Three performances are slated Dec. 8 at 7:30 p.m. at First Parish Church, 9 Cleaveland St., Brunswick; Dec. 11 at 7:30 p.m. at Cathedral of St. Luke, 143 State St., Portland, and Dec. 13 at 4 p.m. at St. Mary’s Church, 43 Foreside Road, Falmouth.

‘Broadway at Good Theater’

Early every December, Good Theater stages a concert that is based on Broadway musicals and starring at least one Broadway actor plus a dozen or so local thespians. The show is written by Good Theater artistic director Brian P. Allen, who also selects the music and directs.

I’ve known Allen for about 20 years, and we share many of the same tastes in musical theater. He’s an expert on the history and traditions of Broadway, and this annual production is one way he gets to share his vast knowledge with the public.

This year, “Broadway at Good Theater” will be a tribute to the 1930s and all of the amazing musicals to open on the Great White Way during that decade. Shows written by George and Ira Gershwin, Cole Porter, Richard Rodgers and Lorenz Hart, Irving Berlin and Jerome Kern among many others will be highlighted. Kenita R. Miller will be the featured guest star. Her Broadway credits include “The Color Purple,” “Ragtime” and “Xanadu.”

She will be joined by up-and-coming New York singer Nicholas Callaway Foster plus many local actors who have graced the Good Theater stage over the past few years.

“Broadway at Good Theater” will be performed at the St. Lawrence Arts Center, 76 Congress St. in Portland (top of Munjoy Hill) at 7 p.m. Dec. 2-3; 7:30 p.m. Dec. 4; 3 p.m. and 7:30 p.m. Dec. 5, and 2 p.m. Dec. 6. Call 885-5883.

Portland String Quartet

Maine’s songbirds have mostly migrated south for the winter, but there’s an opportunity to hear some classically melodic avians this Sunday when the Portland String Quartet plays its third concert of the 2015-2016 season.

Comprising violinists Dean Stein and Ron Lantz, violist Julia Adams and cellist Andrew Mark, the PSQ has been at the leading edge of Maine’s cultural life since it was founded in 1969.

This Sunday’s program comprises two mainstays of the classical repertoire plus an important 20th-century work. Opening will be one of many string quartets by Franz Joseph Haydn, who was the first composer to fully explore this format. The item chosen for Sunday is subtitled “The Birds,” so named for a bird-like melody that’s played by the violins.

Ernest Bloch’s String Quartet No. 2, written in 1946, is the most modern work. The PSQ has recorded the entire opus of Bloch quartets, which won great praise from a New York Times reviewer.

The finale will be Ludwig van Beethoven’s String Quartet No. 15, which is a large and complex work that dates from the end of the composer’s creative life.

Catch the Portland String Quartet at Woodford’s Congregational Church, 202 Woodford St. at 2 p.m. Dec. 6. Call the LARK Society at 761-1522.

Christmas at the Cathedral is an annual concert of the Choral Art Society and invited guest artists. It’s slated for four performances in Portland Dec. 5-6.