“This next one is about being abducted by aliens,” Mallrat whispered into the mic, halfway through her performance.

Touring the U.S. a year after the release of her debut album “Butterfly Blue,” Mallrat (born Grace Kathleen Elizabeth Shaw) arrived with all the delicate dreaminess of her recognizably catchy pop songs. The Australian-born singer-songwriter might have been on her first week of tour, but Sept. 12, she drifted into Bimbo’s 365 with ease.

Her outfit — a ruffled red top and pleated skirt — perfectly matched the flowy, romantic lushness of her music. Crooning about love in polished black loafers and a red hair ribbon, she embodied a playful tenderness.

Shaw walked on stage to the celestial surge of her smash hit “Wish on an Eyelash,” a minute-long flash of lovestruck longing that ended too quickly, saturating the venue with a swell of euphoria. 

Surprising the crowd, she followed with the faster rap beat of “Surprise Me,” a collaboration with Azealia Bank, priming the room for bursts of energetic excitement grounded by her rich and lingering vocals as she bounced across the stage. The song’s warm, echoing end slipped perfectly into the smoother pop of “Nobody’s Home,” returning to Shaw’s comfortable, looping chorus: “Nobody’s home so I sing my songs about you.”

Casting simple, intimate scenes of dancing in socks and waiting home alone, Shaw sang with a comfortable lightness as she echoed her chorus. But after sipping some water, she pursed her lips and twisted with a touch of self-aware timidity, “Not even going to lie. I’m in a shy mood tonight guys. I’m feeling shy.”

As she drove through her setlist, including a smattering from her 2018 EP “In the Sky,” she found a rhythm between songs, twirling through the stage and singing pressed close to her guitarist. With “Better” and “UFO” (the alien abduction song, by the way) Shaw seemed to vibrate with drawn-out vowels and rising inflections. Sometimes lyrically repetitious, her performance added needed vibrancy, showcasing the soothing pull of her voice.

While it took her a little while to warm up, Shaw’s casual, off-the-cuff dialogue felt more authentic. Asking the crowd if a stuffed animal on stage should be called “Jorts” (her preferred suggestion) or a singular “Jort” (her band’s suggestion), she smiled, wrapping her hands around the mic. “Was that a ‘boo’ I heard for Jort?” she asked, as the crowd laughed, “Interesting. I’ll have to keep that in mind.”

Peering into a cluster of fans pushed to the front, she bent over the lip of the stage to hold their hands. She returned to the mic with letters and a lit-up flower crown from the crowd, which flashed from behind her for the rest of the set. Gesturing for the audience to squeeze close, she darted around stage, snapping photos with a small camera. As she moved, the large fox tail tied to her skirt swayed at her hip.

Introducing the EDM-heavy, echoing “R U High,” Shaw talked about her changing interest in musical genres.

“When I go into the studio to work with someone I haven’t worked with before, usually the conversation starts with ‘What thing do you want to work on?’ ” she said. “But I want to emulate all the artists I feel inspired by. We could try a country song, but we could try putting an auto-tune on everything.”

Rapidly flashing white lights punctured the darkness of the stage as the crowd vibrated to the repeated phrase “Are you high?,” transforming the calmness of the pit into a dizzying club-like illusion.

Shaw’s hunger for new sounds added to the show’s energetically unpredictable structure. Shifting from echoey pop to rap collabs and EDM, Shaw’s shining voice proved the only constant, even if she always returned to her slower pop roots.

Before she closed with the hopeful “Rockstar” she faded into the sentimental piano of “Charlie,” overlaid with echoing backup vocals and gentle snapping. Someone launched a green bra from the center of the crowd. Shaw picked it up, smiled and proved she was a rockstar.