Butterflies in the stomach. Sweaty palms. Accelerated heart rate. Dry mouth. Tightness in swallowing. Difficulty in focusing. Cold hands and feet.

It’s time to perform.

Millions of musicians, actors, public speakers — or anyone doing something in front of an audience, no matter how small — know the above symptoms well: They’re signs of performance anxiety, also called stage fright, and can be debilitating, even for a professional performer. National surveys of what makes Americans fearful consistently show public speaking at the top of the list.

For Boston filmmaker John Beder, performance anxiety drove him out of a career as a professional percussionist and into producing a documentary about how professional musicians and others cope with it. That 78-minute documentary, “Composed,” will be screened for the public at 7 p.m. Wednesday at Baylor University, courtesy of Baylor’s School of Music.

The subject — and the need to address it for young performers — made School of Music Dean Gary Mortenson more than amenable to hosting a public screening of the movie, followed by a panel discussion on the subject with Beder on the panel.

“All of us deal with performance anxiety — with no exceptions,” said Mortenson, who has a background in trumpet performance in addition to his administrative experience. “I feel an obligation to Baylor and the greater public to bring information on something that’s pretty much universal.”

Music training often emphasizes theory, instrumental technique and repertory, while subjects such as performance anxiety aren’t addressed overtly or, as Mortenson noted, admitted openly.

For Beder, the psychological tension that built before performing often caused his hands to twitch and eventually led him from his studies at Boston University into another field. “I just left music. This feeling of watching my hand shake while I was playing a snare drum. . . . “ he said. Though stage fright is often associated with performers at the front of a stage, soloists or actors, percussionists have an equally strong fear of a public mistake, Beder said: a missed beat that throws off an ensemble, for instance, or a cymbal crash at the wrong time.

The film that became “Composed” started initially as Beder’s exploration of musicians who used the beta blocker propranolol, a prescription medicine for heart disease, to control the physical symptoms of stress. What he found was even more interesting: how performance anxiety affects even veteran musicians — performers with such elite groups as the New York Philharmonic, the Cleveland Orchestra, the Los Angeles Philharmonic and the Philadelphia Orchestra — and how constrained they felt in talking about it.

“It shocked me the number of people who said, ‘Yes, I get nervous’ . . . and how they wished they could be more open about it,” said Beder, presently on a national tour with his wife to support the movie. “I hope this movie is empowering, to let (people with performance anxiety) know they’re not alone.”

“Composed” interviews professional musicians, students, therapists, doctors and more to reveal how universal performance anxiety is and the varied approaches to coping with it.

For Beder and some performers, stage fright raises an existential question: What happens if you prepare for a life as a performer, but can’t get past a crippling anxiety about doing that, whether in front of an audience of thousands or an audition before a handful?

Baylor University professor of acting Steven Pounders, an Equity actor who often performs in Dallas- and Austin-area productions, says performance anxiety is a crucial subject for an actor and noted pioneering Russian actor and teacher Constantin Stanislavski addresses it overtly and by implication throughout his textbook “An Actor Prepares.”

Though many think that the major effect of stage fright is forgetting one’s lines in a play, it can have a less visible, but equally damaging result on a performance. “Worry about your performance takes away your concentration . . . actors who lose their concentration ultimately lose their honesty (in performance) and that results in cliched acting,”

Time spent in learning one’s lines and role goes far to build a confidence that minimizes the effect of stage fright, but so does training in narrowing one’s focus from a watching audience to the action and dialogue at hand. Pounders finds that when stage fright hits and makes his knees weaken, he focuses on what’s onstage in front of him: the actors sharing the stage and the scene that’s being played.

The musicians interviewed in “Composed” share their tips on coping with performance anxiety, from meditation to medication. One common strategy is what untold music teachers and acting directors have preached for centuries: practice, practice, practice.

“The number one strategy is preparation . . . Failure often comes with a lack of preparation,” said Mortenson.

Practicing or preparing in front of someone else, such as a friend helping with an actor’s lines or a teacher listening to an exercise, is important to build toward a big performance. “If your first recital is at Carnegie Hall, you’ve made a mistake,” Mortenson said.

(Some of Baylor’s most talented student musicians, incidentally, are shooting for a bid at New York’s Carnegie Hall this Sunday with the final public round of the Semper Pro Musica competition scheduled from 1 to 7:30 p.m. at Jones Concert Hall.)

By tackling the question of stage fright head-on, talking about it openly and developing , performers both professional and amateur have tools at hand to keep it in check.

“If you have butterflies, teach them to fly in formation,” said Mortenson.

Tribune-Herald entertainment editor