When is a cover of a cover worthy of attention? When it involves two young sisters harmonizing and providing their percussion on Robyn's 'Call Your Girlfriend.'

Twelve-year-old Lennon Stella and eight-year-old sis Maisy base their cover on the one by Erato, a Swedish girl group who performed 'Call Your Girlfriend' using only their voices, their hands and a few small plastic containers. The Stellas, who have their names written over their heads for easy identification, use the same technique as they sing Robyn's 2011 dance-pop hit.

With two microphones in front of them to pick up every note, the girls faithfully reproduce Erato's cover of the Robyn track, which hit No. 1 on the Hot Dance Club Songs chart and earned a Grammy nomination.

The Stellas are capable of more than just re-creating viral performances, as their YouTube account  shows. The siblings have posted a dozen videos, including a cover of Jason Mraz's 'I Won't Give Up' on which Lennon plays guitar.

Watch Lennon and Maisy Stella Perform 'Call Your Girlfriend'