After four consecutive years of significant growth in attendance, the Sisters Folk Festival will expand its offerings in 2011 to include a new venue and more music at established venues in an effort to meet demand.

The festival — to be held Sept. 9-11 — will add Slick’s Que Co. to its roster of venues, bumping the total number of stages scattered around Sisters from six to seven. Slick’s will host finalists in the festival’s songwriting contest on Friday and emerging artists on Saturday.

Additionally, Angeline’s Bakery will host music on Friday night and The Depot Cafe will host sets late Saturday, a first for both venues. All three new offerings are designed, in part, to give attendees more choices for things to do after music ends on the main stage at 10 p.m., SFF Artistic Director Brad Tisdel said last week.

More late-night choices should ease pressure on Bronco Billy’s Ranch Grill and Saloon, which can hold only a few hundred revelers but has become a popular destination among fest-goers looking to stretch their day into the wee hours.

The team behind the Sisters Folk Festival is celebrating the event’s 16th year by tackling issues that come with increasing popularity and growing crowds, Tisdel said.

“In the last four years, we’ve been between 20 and 30 percent over the previous year in ticket sales, consistently, every year,” he said. “So with that comes growing pains and (the question of) how do we respond to more people coming to our event.”

For years, SFF drew in the neighborhood of 1,500 to 1,800 folk fiends annually, Tisdel said. Last year, the festival pre-sold nearly 1,800 tickets and Tisdel estimated that about 3,000 people attended throughout the weekend.

That growth is also reflected in SFF’s programming, said Tisdel, who books the acts and sets the schedule of performances.

“Four years ago, we had the main stage and the Sisters Art Works stage going at the same time on Friday night,” he said. “This year, we’ll have five stages going at the same time on Friday night.

“The most important piece for us is how do we keep the integrity of the event and have our patrons and artists have a great experience?” he continued. “How do we do that well?”

Unlike many music festivals, the SFF is located in town, intertwined with the streets and buildings of Sisters, and most of its stages are inside businesses with established capacities. Expanding the capacity of the stages isn’t as easy as ordering larger tents.

“Last year, I put Hot Club of Cowtown at Bronco Billy’s on Saturday at 10 p.m.,” Tisdel said. “Well, there’s 3,300 people, let’s say, in town, and half of them want to see that act, and the venue holds 250 people. That’s a problem.”

One potential solution would be to place bigger names only in venues with bigger capacities, but both Tisdel and the SFF’s board of directors worry about eroding the uniquely intimate musical experience that has helped fuel the festival’s success.

Another potential solution: Continue to have bigger names at smaller venues and make sure attendees know that if they must see a certain artist on a certain stage, they should show up early.

“Then you start standing in lines,” Tisdel said, “and then you have people who aren’t that fired up about standing in lines.”

SFF’s focus this year will be a combination of moves intended to “spread the festival out a little bit more” by not only adding venues, but making good scheduling decisions (all acts at SFF play at least two sets, usually on two stages over two days) and educating people about the possibility of some venues filling to capacity.

“We’re not trying to expand for the sake of getting bigger. We’re trying to expand to accommodate the fact that we’re getting a little bit bigger,” Tisdel said. “But there’s a cap. And I think at some point, if the slope kept going the way it’s been going, we would probably start selling out at a certain number.”

Success is not only measured in ticket sales at Sisters Folk Festival, Inc., the nonprofit group that operates the annual music festival as well as a songwriting academy, the Americana Project music program in local schools, the My Own Two Hands fundraiser and a winter concert series.

Tisdel said the songwriting academy is more popular than ever, the Americana Project recently expanded to take over a instrument-building class at Sisters High School, and My Own Two Hands netted more than $100,000 for music and arts education in April.

Also in April, the organization expanded its staff, adding Americana Project alum Travis Ehrenstrom as assistant festival director and naming longtime employee Katy Yoder development director. Yoder will focus on fundraising, Tisdel said, and Ehrenstrom is examining SFF’s media presence and working to ensure the festival reaches a younger generation in addition to more traditional (i.e. older) folk fans.

No matter who shows up or how old they are, though, Tisdel and his team are dealing with the festival’s growth-related issues with a bottom line in mind.

“The intent is to keep the integrity of the music at the forefront while providing an opportunity for everybody to see whoever they want to see no matter the venue. But we have to be thoughtful in that,” he said. “We don’t want to get bigger for bigger’s sake. We want it to be an intensely cool musical experience.

“We’re grateful and humbled by how we’re doing and what we’re doing,” he said. “We just want to continue to do it really well.”