Poll any number of professional classical musicians on the question of “greatest composer in history” and you’ll likely get a majority answering “Johann Sebastian Bach.”

The 18th-century German was the dominant composer of his era and many of his works are considered masterpieces, beloved by audiences, performers and music scholars.

This Friday marks the inaugural concert in the Portland Bach Experience, a new organization that’s headed by Emily Isaacson, Maine’s up-and-coming musical mover and shaker who is currently best known as the director of the Oratorio Chorale. A total of 16 events, mostly concerts, are scheduled daily through June 17.

(Portland is actually heading into a fortnight of Bach. The Bach Virtuosi Festival follows, but that’s another story for next week.)

It’s a long way from 18th-century European classical music to contemporary Americana, but southern Maine audiences can have both this weekend. In the latter department, the Blues Prophets are slated to play Portland on Friday while Dar Williams follows on Sunday.

Portland Bach Experience

You could call it a series of concerts and other musical events. Emily Isaacson prefers to call it an experience.

As in Portland Bach Experience, a 10-day musical celebration of the works of Johann Sebastian Bach and some of his contemporary composers in the European Baroque Era. The inaugural edition of the Portland Bach Experience debuts this Friday and continues through Sunday, June 17.

Bach, a German who lived from 1685 through 1750, is regarded by many professional classical musicians as the greatest composer in history. He represented the apotheosis of Baroque music, and his works are still frequently heard in concert halls around the world.

Isaacson has programmed 10 days of events – 16 in all – deftly mixing traditional concerts with very innovative non-traditional performances. The major concerts are held at St. Mary’s Episcopal Church in Falmouth, while the other venues are scattered around Portland, including the Portland Museum of Art, a private art gallery in the Old Port and the U.S. Customs House on the waterfront.

PBE opens with Friday and Saturday performances of a pair of Bach’s biggest and best-known works, the Orchestral Suite No. 3 and his “Magnificat,” a vocal and instrumental setting of the “Song of Mary” from the Gospel of Luke. Isaacson will conduct musical forces that include a complete Baroque orchestra, five vocal soloists and a choir.

Monday through Thursday are devoted to alternative presentations of Bach in non-traditional venues. These are central to Isaacson’s basic concept.

“What I am doing is returning the music to the environment in which it was conceived,” she explained. “The concert hall – with its strict rules and etiquette – is a 19th-century invention. Much of Bach’s secular music was premiered at Zimmerman’s, a beer hall for the middle class. At the time, women were forbidden from frequenting these establishments, but they were allowed to attend these concerts. So Zimmerman’s became a place for the opposite sexes to meet. In other words, Bach intended this music to be heard in a venue that was associated with drinking, socializing and flirting. With events like ‘Bach in a Bowling Alley,’ ‘Bach & Beer’ and ‘Suite Ride through Portland,’ I’m trying to return classical music to its natural habitat.”

The second weekend features two programs. On Friday the Diderot String Quartet will be joined by harpsichordist James Kennerley in a concert titled “A Journey Through Baroque Europe.” The Juilliard-trained Diderot String Quartet specializes in Baroque music performed on period instruments. Isaacson greatly admires the foursome.

“The Diderot Quartet is one of the most exciting groups of musicians in North America,” she enthused. “Their fresh and daring approach to 18th- and 19th-century music is exciting, dramatic and deeply expressive. More than once I’ve been moved to tears when they play.”

PBE closes on Saturday and Sunday with a pair of performances of the masterwork of one of Bach’s contemporaries, Antonio Vivaldi’s “Four Seasons.” A set of four Baroque concertos for orchestra, “Four Seasons” is notable for incorporating the sounds of nature: flowing creeks, singing birds, barking dogs, frozen landscapes and warming fires.”

For a complete schedule, ticket info and other details on the Portland Bach Experience, visit PortlandBachExperience.com.

Blues Prophets

Portland may be getting its inaugural “Bach Experience” this weekend, but the Port City has been experiencing other fine musical ensembles for a long time, especially since the 1970s.

Several of the groups that formed during that decade are still performing. In classical music, the Portland String Quartet launched its stellar career back then. In Americana, Schooner Fare and Devonsquare were two closely related trios that rocked the Holy Mackerel on Commercial Street.

And the Blues Prophets began a run that has now exceeded four decades. They’re still going strong and will return to the Port City on Friday.

The Prophets’ shtick is simple: “straight-up Chicago-style blues,” according to co-founders D.W. Gill, who plays harmonica and handles some of the vocal duties, and Doug Wainoris, vocalist and guitarist. Gill and Wainoris are the only original members among the current lineup of five.

Over the years the Blues Prophets have played alongside James Cotton and Muddy Waters, but their base is in Maine, and they have legions of local fans who turn out in force to hear them play. “We might take out extra insurance ‘cause they might rock the roof right off the room,” joked Al Leighton, a director of host One Longfellow Square.

Catch the Blues Prophets at 8 p.m. June 8 at One Longfellow Square, corner of Congress and State in Portland. Call 761-1757.

Dar Williams

Dar Williams is another Americana artist who’s appearing in Portland this weekend. A native New Yorker, Williams launched her career as a singer-songwriter in the folk-pop vein in Boston in the 1990s. Since then she’s released 20 albums, the most recently in 2015.

Williams writes from personal experience, which of course includes hundreds of thousands of miles of travel and thousands of people she’s encountered along the way in hundreds of cities and towns.

Reviewing a pair of concerts in 2011, Hendrik Hertzberg commented in the New Yorker: “I don’t really have the vocabulary to do her work justice, so I’ll just say that her songs are beautiful. Some are like finely crafted short stories. They are, variously, devastatingly moving, tenderly funny, subtle without being in any way inaccessible, and utterly fresh — not a cliche or a clunker in her entire songbook, which now numbers around a hundred recorded original compositions.”

Catch Dar Williams at 7 p.m. June 10 at One Longfellow Square, corner of Congress and State in Portland. Call 761-1757.

Diderot String Quartet are among the many professional musicians who will appear during the inaugural Portland Bach Experience, which runs June 8-17.