Watch Lennon and Maisy’s Pristine Cover of Charli XCX’s ‘Boom Clap’

Two years after their glorious cover of the Lumineers’ “Ho Hey,” Lennon and Maisy Stella are putting their unique stamp on another tune outside of Nashville’s borders. The singing siblings have stripped down Charli XCX’s “Boom Clap” in a harmony-rich, production-bare version of the pop hit. Watch above as Lennon, 15, strums an electric guitar while delivering the tune in her crystal-clear, angelic voice, harmonizing and trading lines with her equally ethereal 11-year-old sister.

The Stella girls, who play Connie Britton’s daughters on ABC’s Nashville, provide some of the most memorable musical moments on the show. After singing “Ho Hey” on the first season, the song charted Top 40 on country radio. Originals they’ve performed include the poignant “A Life That’s Good” and hooky “Telescope” — with all of their collaborations involving simply two voices and one guitar.

Lennon and Maisy are the real-life daughters of Canadian country duo, the Stellas, who would often let their girls accompany them on stage at various gigs. The sisters remember Maisy being just three years old the first time their harmonies really clicked. “We were opening Christmas presents, and Lennon was singing this whole album,” the youngest Stella told Rolling Stone Country at the 2014 CMA Awards. “I asked, ‘Is it my turn yet? I want to sing!’ And finally I sang [Faith Hill’s] ‘Where Are You Christmas’ with her.”

Outside of the show, Lennon and Maisy have played the Grand Ole Opry about a dozen times, along with various charity and industry events when their school and work schedules allow. In 2012, they released an EP of live performances, followed by a handful of singles in 2014. Their recent, folk-laden cover of Edward Sharpe & the Magnetic Zeros’ “That’s What’s Up” has more than eight million views on YouTube.