It's a Monday night at the 331 Club in northeast Minneapolis, and about eight musicians toggle in and out of a horseshoe of chairs. They take turns strumming the bluegrass sounds of the Roe Family Singers. One of the few players who never subs out is Adam Wirtzfeld.

He's at one end of the arc, closest to the crowd, finessing a bow across his bent and vibrating musical saw. With the saw handle pinched between his legs and his left thumb pressing hard on the tip, Wirtzfeld draws the bow across to produce a sound that wobbles, whirs like an engine, soars like an operatic aria.

Wirtzfeld, like other area saw players, is self-taught and often the only saw player in the room. But this weekend the humble tool takes center stage as Wirtzfeld travels to Richmond, Minn., to teach a musical saw workshop at the Minnesota Bluegrass & Old-Time Music Festival, while fellow Minneapolis player Steve Cook travels to Felton, Calif., to compete at the International Musical Saw Association's annual festival.

"It was many years until I actually saw another saw player live," said Wirtzfeld, 32, who wanted to play stringed instruments as child, got stuck with piano and trumpet, and finally began bowing the saw after hearing it played in the popular recordings of Neutral Milk Hotel.

The instrument, which is used in bluegrass, old time, jazz and pop recordings, spans about one octave. But that doesn't stop the bow -- typically a sturdy cello bow -- from coaxing out a variety of voices. The musical saw can emit eerie screeches or soothing hums.

Some musicians learn to play from family members, but others learn alone before they snuggle their sound into songs appropriate for the saw's quirks. Then they wait for listener reactions and questions, which come without fail after almost every show.

"It's arresting," says Andy McCormick, 39, who plays weekly at the Bedlam Theatre with Dreamland Faces. "It's pure novelty and I love it."

McCormick's saw style is one of playful, dynamic and bizarre sound effects; some accompany silent film showings at the Bedlam Theatre and others accent the Dreamland Faces' aesthetic of accordions, tubas, mandolins and vocals projected through small megaphones. McCormick starts and stops and zips high, piercing notes more often than players like Wirtzfeld and Cook, who usually sustain melodies or counter melodies.

But even novelty playing takes serious work.

"Novelty is something that gets your interest right away, but it's something else that keeps you listening," said McCormick, who lists 20th-century composers Hanns Eisler and Alec Wilder among influences.

Painful to play

Fellow Dreamland Faces player Randall Throckmorton, 41, of St. Paul, said McCormick's ability to play scales and atonal pieces is impressive.

"And it's painful to play [the saw]," he said.

Although each player can choose between authentic tree-choppin' saws or specially made musical saws, there's no way around the instrument's nature: it's a steel sheet that needs to be bent like a reclining "S" to make sound.

"When I first started playing, it took awhile to play more than 15 minutes," Wirtzfeld said. "Now my left hand is vise-like."

Wirtzfeld owns 10 saws -- most of them made for music -- because hardware store saws are made of "crappy metal" these days, he said. To find agile saws, players look at length and compare the width of the tip to the handle.

Sometimes it takes just a flick.

"In a hardware store, we'd often check saws on the rack. We'd pull it off and bend it and snap it a little bit with a finger," said Jack Morris, 72, of White Bear Lake, who learned to play from his father.

Once, Morris found a Swedish-made saw at the store and knew he'd stumbled upon a real find. The memory is so clear, he speaks of it in present-tense.

"Unbeknownst to the sales person, I take it off the rack and snap it with a finger and say, 'Wow, this is good,' and with no more questions, take it home, get the bow out, rosin up the bow, and I'm pleased," Morris said. "As time goes on, I began to realize it was probably a better sounding saw than my father's saw."

Dad's saw was retired. And Morris, after 50 years of playing, doesn't play his Swedish model often anymore either.

"Now it just fits in as a novelty," he said. "I'm pretty rusty on it."

Jamming at festivals

Meanwhile, Cook has taken his playing to the competitive level. In the past year, he has gone from relaxed bedtime playing to jamming in a group at the 331 Club to second place in the California festival.

"To be in a place where other people are playing this instrument was a mind-blower," Cook said of the festival.

He has also peeked in on Wirtzfeld and McCormick and continues to work on new styles.

When Wirtzfeld traveled to New York City in July for a one-day saw festival, he came back humbled and inspired. He listened to players using electric distortion and operatic accompaniment. Despite playing it safe with a familiar Roe Family Singers song during his turn on stage, he held his own.

"I shoulda blown everyone away with my two-note harmonic chops," he joked at his Seward home after the festival.

Saw awe isn't reserved for veteran players at niche festivals. The musicians agree: Casual listeners always react to the instrument.

"You should see the reactions to our YouTube videos," said John Barcay, 48, of Burnsville. He plays saw with the Moss Piglets bluegrass band. "When I get up in front of a crowd, you can see people pull out their cameras."

Barcay also plays a stainless-steel turkey baster and traditional instruments, but said bluegrass music has just enough space for the saw.

"I use it more to support the rest of the band," he said. "I try to keep it in the background because the saw can get loud ... louder than the banjo."

And since saws lack tuning mechanisms, it's up to saw players to play along by ear.

"I'm able to jump in with others," Cook said. "I feel like I'm a musician now."

Tony Gonzalez • 612-673-7415