The first week of May marks the midpoint of spring. Right on cue, two local choral ensembles are offering their spring concerts this Friday, Saturday and Sunday.

The larger of the two is the Portland Community Chorus, numbering more than 100 singers under the direction of Rob Westerberg. PCC’s spring program will be performed Friday and Saturday in South Portland.

On Sunday in Portland, the 15-voice ChoralArt Camerata presents “SpringSong” under the baton of Robert Russell. The two major works date from the 1700s and the 2000s. The latter is considered an exemplar of 21st-century choral art.

On Saturday in Portland, Boston folk fiddle virtuoso Hanneke Cassel will launch her new album tour in Portland before heading west for a fortnight on the Pacific Coast. The new album is titled “A Trip to Walden Pond,” inspired by the famous little water body where Henry David Thoreau once lived and wrote his most inspired book.

DaPonte String Quartet wraps up its 2016-2017 subscription series with a string of five concerts performed over an eight-day span. The first is in Brunswick on Sunday.

Portland Community Chorus

The Portland Community Chorus is one of Maine’s largest musical ensembles. Numbering about 150 – with about 100 performing at any one time – the PCC traces its origins to collaborations with Portland Symphony Orchestra.

The PCC still works with the Symphony (it forms the basis for the Magic of Christmas Chorus), but it has since evolved into an independent ensemble with an identity and schedule of its own.

I’ve been attending PCC concerts for a couple of years now. I’ve enjoyed them thoroughly and I’ve already reserved my tickets for this weekend.

Director of the PCC is Rob Westerberg, a past president of the Maine Music Educators Association; he presently leads the chorus at York High School. Westerberg has a very distinguished career with both the PCC and several high school groups, leading them to performances at New York’s famed Carnegie Hall.

This weekend’s spring concert has two distinctly different parts. The first half focuses on well-known classical European composers: George Frideric Handel, Johann Sebastian Bach, Franz Schubert and Felix Mendelssohn. The second half embraces mostly 20th-century music. West End-Broadway composer Andrew Lloyd Webber is best known; others include two prominent Americans, K. Lee Scott and Ira Randall Thompson. The latter got his start in music at the family vacation home in Vienna. (That’s the Vienna in Maine, near Augusta.)

Two performances are slated for South Portland High School, 637 Highland Ave., at 7:30 p.m. May 5 and 2 p.m. May 6. Call 370-5320.

ChoralArt Camerata

ChoralArt Camerata is the smallest of three sub-units of the group formerly known as the Choral Art Society. This smallest and most intimate ensemble will perform on Sunday, led by Robert Russell, the dean of Maine’s choral directors.

Russell served about 30 years as professor of choral studies at the University of Southern Maine School of Music. He’s helmed ChoralArt for more than 25 years.

“SpringSong” is the name of the program, and Russell has selected two major works. The first is Wolfgang Amadeus Mozart’s “Vesperae solennes de confessore,” a stunning six-movement work setting texts from the traditional Gregorian vespers service. Guest pianist Amanda Raymond will accompany the 15 voices of the Camerata.

The second half of the program features modern works revolving around an ancient theme: Earth, Air, Fire and Water. The centerpiece of the modern programming is Eric Whitacre’s “Leonardo Dreams of His Flying Machine,” a choral work that dramatizes Leonardo da Vinci’s speculation about the possibility of human flight, three centuries before the Wright brothers at Kitty Hawk.

Russell believes that Whitacre’s work is the best example of choral art of the new millennium.

ChoralArt presents “SpringSong” at 4 p.m. May 7 at Williston-Immanuel United Church, 156 High St. in Portland. Call 828-0043.

Hanneke Cassel

One of America’s foremost exponents of traditional Celtic fiddling has just released a new CD, and she’s about to launch a national tour in support. The artist is Hanneke Cassel, who was raised in Oregon but began getting noticed in the Celtic music world in the 1990s when she was a student at Boston’s famed Berklee College of Music.

Among her honors, Cassel was U.S. National Scottish Fiddle Champion three times, copping the junior division in 1992 and 1994, and taking the senior (open) honors in 1997. Twice she received special honors and scholarships from Berklee.

Cassel has many strong Maine musical connections, with frequent collaborations with Darol Anger and Brittany Haas, and she’s a regular performer in Portland, where I’ve seen and admired her several times.

“A Trip to Walden Pond” is Cassel’s 10th album, inspired by a visit to the tiny Massachusetts locale made famous by Henry David Thoreau’s groundbreaking book. It was released this past April 14, Cassel’s 39th birthday.

The tour begins Saturday in Portland, then move west to the Pacific Coast for two weeks. Bandmates on this tour include cellist Mike Block and guitarist Keith Murphy.

Catch Hanneke Cassel’s “Trip to Walden Pond” CD release tour at 8 p.m. May 6 at One Longfellow Square, corner of Congress and State in Portland. Call 761-1757.

DaPonte String Quartet

Wrapping up its 2016-2017 subscription season, the DaPonte String Quartet will appear five times in five venues over an eight-day period, covering a geographic span between Rockport and Portland.

Three works are planned. The opener, “Arcadiana,” is a seven-movement string quartet written in 1994 by contemporary British composer Thomas Ades. “Arcadiana” is meant to evoke images of paradise, using a variety of harmonic techniques and rhythms. It will be followed by Samuel Barber’s “Adagio for Strings,” one of the most-often played compositions in American classical music.

Concluding is a comparatively seldom-heard piece, Franz Schubert’s Cello Quintet in C Major. For the second cello, the DSQ has engaged Scott Kluksdahl, a professor of music at the University of South Florida who also plays with the Veronika Quartet.

The schedule is May 7 at 3 p.m. at the Unitarian Universalist Church, corner of Middle and Pleasant streets in Brunswick; May 11 at 7:30 p.m. at the Maine Jewish Museum, 267 Congress St. in Portland; May 12 at 7:30 p.m. at Lincoln Theater, 2 Theater St. in Damariscotta; May 13 at 4 p.m. at St. Columba’s Church, 32 Emery Lane in Boothbay Harbor; May 14 at 3 p.m. at the Rockport Opera House, 6 Central St. Call 529-4555.

Boston fiddler Hanneke Cassel has just released a new album, and she’s launching a supporting tour on Saturday in Portland.