A column of news and updates of the Boston Celtic Music Fest (BCMFest), which celebrates the Boston area's rich heritage of Irish, Scottish, Cape Breton music and dance with a grassroots, musician-run winter music festival and other events during the year.

During its two years of existence, BCMFest's Celtic Music Monday series at Club Passim in Harvard Square has featured fiddles, flutes, accordions, pipes, even the bones and bodhran. But the instrument in focus this month will be the human voice - and it won't just be sounding from the stage.

On July 13, at 8 p.m., Celtic Music Monday presents "All Chorus Songs, All the Time (Reprise)," a repeat performance of a concert held last December that proved such a crowd-pleaser that BCMFest organizers decided to bring it back for another round.

The featured performers for the July 13 event are all well-versed in leading sing-alongs, whether on stage, in pubs and parlors, and in less conventional settings -- even on the deck of a boat cruising around a harbor.

Lynn Noel is a familiar figure in the Greater Boston folk song scene, as a member of the Gloucester Hornpipe and Clog Society (which performed at BCMFest 2009) and a leader of regularly occurring sea chantey and pub sings in the area, such as The Skellig in Waltham. She is a fine instrumentalist, accompanying herself on guitar and mountain dulcimer, but her unaccompanied singing is equally, if not more, powerful. Noel also has appeared on several recordings, including Gloucester Hornpipe and Clog Society's 2008 release "Liberty!"

Michael O'Leary didn't think of himself as a singer until well along in life, but he's more than made up for lost time, appearing at BCMFest, Irish Connections Festival, New England Folk Festival and other festivals and concert venues in New England. He also organizes BCMFest's annual music cruise in Gloucester Harbor. In 2003, O'Leary was co-recipient of a Massachusetts Cultural Council Traditional Arts Apprenticeship grant that enabled him to study the traditional Irish sean nos singing style from Bridget Fitzgerald.

Scottish native Jerry Bell is known as an all-around entertainer, raconteur, and life of the party, keeping audiences in stitches when he's not leading them in songs. But Bell's interest in folk and traditional music runs deep and assumes many forms: He is an avid fiddle player in the Scottish style (although he can more than hold his own in an Irish session), a superb bagpiper, and more than proficient on such instruments as flute, guitar, bodhran and banjo. Bell and his wife Nancy also have earned the Parent's Choice Gold Award for their family-oriented folk music, stories and dance programs.

Sean Smith took up traditional music back in high school and has played in the Boston area for some 25 years, appearing as a soloist, in bands, or in collaboration with other musicians at venues such as Club Passim, ICONS, the Blackstone Valley Celtic Festival, the Elysium Arts Folk Club, as well as the Concerts at the Captain's House and Notlob Kitchen Concerts series. A member of the BCMFest board of directors, he is a co-organizer and frequent emcee for the Celtic Music Monday series and instigator of the "traditional Celtic Music Monday sing-along" that often begins each show.

(O'Leary, Bell and Smith also are notorious for their random appearances and offerings of whimsical, humorous - if not downright sophomoric - songs during BCMFest's Saturday schedule.)

This quartet promises a selection of chorus songs that runs the gamut from comic to serious, from Celtic traditions to more contemporary sources, and on all manner of subjects: love, work, drink, war and fellowship, to name a few.

Based on how well the last "All Chorus Songs" night went, Smith feels there's every reason to think this month's "encore" will be equally popular. "Boston is just a great singing community, especially when it comes to folk and traditional music. You've got Revels, the monthly MIT Chantey Sing, events at the Irish Cultural Centre of New England, for example, and any number of semi- or informal get-togethers at pubs, coffeehouses or private homes. It doesn't matter whether or not you're a ‘professional' singer; the point is simply to participate, to add your voice to those of everyone around you."

And that, Smith adds, dovetails neatly with BCMFest's community-participation doctrine. "People don't want to be just passive consumers of music - they like to feel engaged," he explains. "BCMFest is built around that, whether it's inviting members of the Boston music community to apply to perform at the festival, to volunteer for BCMFest, or to get up and dance at the Boston Urban Ceilidh. And with Celtic Music Monday, BCMFest tries to organize events that engage people in some way, whether it's a ‘trad to the bone' kind of presentation, or one with a more modern approach to Celtic music.

"So, a night of chorus songs," Smith adds, "is about as participatory and engaging as you can get."

Smith says there will doubtless be some "old familiars" sung at the concert, but the event also can be an opportunity for some to learn a new song or two. "Our motto is, ‘If you don't know the chorus already, you will.'"

Tickets for Celtic Music Monday are $12, $6 for members of Club Passim, WGBH and WUMB. For reservations, go to www.clubpassim.org or call 617-492-7679.

All a-Twitter

BCMFest is already on Facebook and Myspace, as well as the Web. And now, BCMFest has joined Twitter. Just go to twitter.com and search for "BCMFest."

For more information on BCMFest, see www.bcmfest.com you can also sign up for the BCMFest e-mail list via the Web site.