Heartfelt songs, striking vocals and relaxed informality will highlight a series of acoustic concerts at One Colorado’s courtyard this week. Having kicked off with Katie Ferrara on the 25th, Happy Hour Week continues with performances by native New Zealander Eden Iris (tonight, Thursday, April 26), Eagle Rock’s Eric Kufs (Saturday, April 28), Pasadena-raised soulman Chris Pierce (Sunday, April 29) and pop singer-songwriter Chelsea Williams (Tuesday, May 1).

Williams, who grew up in Sun Valley listening to her songwriter mom jam with friends in their living room, started her career busking at Glendale Marketplace. Before long she was setting up her acoustic guitar and amp on Santa Monica’s Third Street Promenade, where she’s been performing for over 10 years — and where Blue Elan president Kirk Pasich spotted and subsequently signed her. “Boomerang,” released by Blue Elan last August, is more mature and polished than Williams’ first three, self-released albums, an ear-friendly blend of winsome sweetness (“Anything Worth Saving,” “Fool’s Gold”) and sober introspection (“Out of Sight, Out of Mind”).

Since then Williams has been opening shows for labelmates Jack Tempchin and Poco’s Rusty Young, in addition to playing wineries and concert halls. Between tours, the poised Downtown LA resident sometimes performs with the Salty Suites at the Coffee Gallery Backstage in Altadena, and still sometimes busks on the Promenade (“It’s kind of like a meditation for me”). These days her solidly rhythmic guitar playing is augmented by a looping pedal, which helps recreate the percussion and harmonies heard on “Boomerang.”

There’s a definite appeal to nightclubs set up with proper acoustics for listening, but — not unlike Kufs, who also busks regularly — Williams says performing on the street and in other public settings compelled her to grow musically, and inspired her to figure out creative ways to emotionally reach people. “I feel that’s helped in some ways with my performance in other venues, learning different ways to get people to stop and pay attention,” she says.

“You take away the barrier of the stage and the lights. There’s this unspoken rule in a club where the audience and the performer are like two separate locations, almost, even though you’re in the same room; there’s that invisible fourth wall. But when you’re just playing on the street it becomes like more of a conversation, and I feel like the connection’s deeper. Just being able to meet somebody that I was never going to meet before who had no intention of going to a live show that day, and make them stop and listen, and then hand them a CD personally and have that unique personal interaction. …

“For me, it’s sort of a response to the whole explosion of social media and how that seems to connect you to people — and it does, it’s an amazing tool. But at the same time you’re connected you’re separated also; you’re not looking at the person’s face, you’re not having a direct conversation with them.” n

Chelsea Williams performs at One Colorado, 41 Hugus Alley, Old Pasadena, at 7 p.m. Tuesday, May 1; seating is open and free to the public. Info: (626) 564-1066. Chelseawilliams.com, onecolorado.com