Accent and dialect coach Gillian Lane-Plescia had a roomful of theater devotees practicing, in unison and in a crisp British accent, a sound that the English make but that Americans usually don't — the short O.

She asked them to recite, using the kind of prim O's that might feel at home on "Downton Abbey": "Tom has got to stop knocking the tops off the bottles."

Lane-Plescia asked if the movement of their jaws felt differently saying the O's that way rather than as an American would, and they nodded.

This session was all part of the 12th annual Goodspeed Festival of New Musicals being held this weekend in East Haddam. As the name suggests, the festival showcases new musicals, but it also offers seminars from theater professionals on a wide range of topics — including accents.

Over the course of three days, the festival has been featuring staged readings of "Picnic at Hanging Rock" by Daniel Zaitchik and Joan Lindsay on Friday and "ZM" by Mark Hollmann and Greg Kotis, who won Tonys for "Urinetown," on Saturday. It will feature "Row" by Daniel Goldstein and Dawn Landes on Sunday.

The festival also has boasted theater tours, cabaret performances and previews tied to the Goodspeed's upcoming season.

And there were the Saturday seminars. The speakers included Jack Viertel, who is the senior vice president of Jujamcyn Theaters (which owns and operates five Broadway theaters), the artistic director of the Encores! series and author of the 2016 book "The Secret Life of the American Musical: How Broadway Shows Are Built"; and Michael Rubinoff, producer for "Come from Away," which was at Goodspeed's 2013 festival and will open on Broadway on March 12.

Lane-Plescia, who lives in Preston, has her share of Broadway credits on her lengthy resume. She has worked with actors on such Broadway productions as "A Gentleman's Guide to Love and Murder," "War Horse" and "Priscilla Queen of the Desert."

Her focus on Saturday was the "standard British accent," the way people in America might expect the British upper class to speak. She demonstrated certain elements that were different for the two groups — Americans use a "long A," for instance, whereas the "standard British accent" would require a "broad A," so that "ask" might sound more like "ahsk."

Lane-Plescia detailed other variations between the ways the two groups talk. The British, for example, tend to have a wider pitch range. American speech is more measured, while British people emphasize important words more strongly than Americans do.

When she works with actors, Lane-Plescia encourages them to use often the accents they're trying to learn, perhaps when they're shopping or when they're making phone calls, so that it starts to feel natural.

In another Goodspeed Festival seminar, Tony Award-winning lighting designer Ken Billington — whose Broadway shows include the original "Sweeney Todd," the revival of "Chicago," and the upcoming "Sunday in the Park with George," starring Jake Gyllenhaal — spoke about his work. He developed an interest in lighting when he was in fourth grade, and, at age 19, he became assistant to renowned lighting designer Tharon Musser. Eventually, at her urging, he struck out on his own.

"I cannot paint. I cannot draw. ... But I can paint with light," he said.

Part of what a lighting designer does, he said, is this: "What I need to do is tell you all about the emotion, when the curtain goes up, of what you're going to be seeing." If the curtain rises on a bright pink room with sunlight streaking through the window, that gives one message to the audience. If, though, it rises on someone standing in a single downlight and that person is in shadow, Billington cracked, "You'll say, 'Well, I guess we're not going to laugh the next two hours.'"

Another aspect of what a lighting designer does is to subtly focus theatergoers' attention. "You should be looking here, not over there," he said.

Ultimately, lighting needs to serve the piece, not call attention to itself.

"I always say the best reviews I get are no reviews. If you don't know I was in that theater, then I've done my job really well. ... You should come out of the theater saying the show was great," Billington said.

k.dorsey@theday.com