Bonny "Babes" - There'll be a distinctive Caledonian feel to this month's BCMFest Celtic Music Monday concert, which features some of Greater Boston's most outstanding female musicians in the Scottish tradition. "Babes in Scotland," which takes place Sept. 14 at 8 p.m. in Harvard Square's Club Passim, will explore the new and the old in Scottish music and song, and how centuries-old traditions have joined with contemporary influences to create exciting sounds.

Presiding over the evening's festivities will be Hanneke Cassel, whose innovative fiddling exemplifies the ancient-modern dynamic in Scottish music. A former US National Scottish Fiddle Champion, Cassel has performed and taught across the US, Scotland, Sweden, China, New Zealand, France, England, and Austria, working as a soloist and also playing with the Cathie Ryan Band, Childsplay, and Halali. She has made guest appearances with such luminaries as Cherish the Ladies, Alasdair Fraser, Aine Minogue, and Joey McIntyre (from New Kids on the Block).

Among others joining Cassel on stage will be fiddler-vocalist Hannah Read, an Edinburgh native and Berklee College of Music student who is a member of the inventive Folk Arts Quartet – which plays "chambergrass," a mix of folk and classical styles; Anne Hooper, a two-time National Scottish Fiddle Champion and a mainstay of the Royal Scottish Country Dance Society Boston branch, the first RSCDS branch to be established outside Scotland; and Katie McNally, an emerging talent among the Boston area's next-generation fiddlers who has studied and played with Cassel.

The concert will be an "in-the-round" affair, Cassel says, with the performers playing as an ensemble, and in smaller combinations or solos. "We think this format will give a really good idea of different aspects of Scottish music," she says. "With Anne, you hear the 'classic' country-dance side of Scotland. Hannah has a very contemporary sound to her singing, with some jazz and pop influences, as well as folk and traditional. Katie and I play what might be called the 'American' style of Scottish music – it's not Appalachian or Texas, but definitely American."

One question Cassel often hears is, "What's the difference between Scottish and Irish music?" There's ample explanation to be found in music theory, according to Cassel, but she also likes to express the answer in metaphorical, even geographical terms.

"I think of Scottish music as related to the landscape; the rugged, severe, square features of the Highlands, for instance. The grace notes in Scots music are more percussive and flamboyant, so it has this up-and-down, vertical quality, where Irish music is more lilting, swirling.

"With Irish music, I picture the musicians kind of huddling in a corner of the room; with Scottish music, they're up on the tables," she quips, adding, "Not that we're planning to stand on tables when we play at Celtic Music Monday, of course. But there's sure to be some excitement."

Tickets for Celtic Music Monday are $12, $6 for members of Club Passim, WGBH and WUMB. For reservations, go to clubpassim.org or call 617-492-7679.For more information on BCMFest, see bcmfest.com; you can also sign up for the BCMFest e-mail list via the website.