LOS ANGELES (AFP) - The soulful 23-year-old R&B performer H.E.R. pulled an upset in scooping the Grammy for Song of the Year on Sunday (March 14) for her justice-minded song I Can't Breathe, which tackles black pain and police brutality.

The guitar virtuoso's single - which debuted in June 2020 in the wake of mass anti-racism protests following the death in police custody of a black man, Mr George Floyd - bested competition from Taylor Swift, Beyonce and Billie Eilish to win top songwriting honours.

I Can't Breathe is a phrase echoing the final words of Mr Eric Garner, who died after New York police placed him in a chokehold while arresting him on suspicion of selling loose cigarettes.

Mr Floyd, who died as a Minnesota policeman knelt on his neck for nearly nine minutes, said the same words as he begged for mercy.

It has become an ubiquitous chant at Black Lives Matter protests against police brutality, and in her bluesy song filled with wrenching lyricism, H.E.R. asks why the three words are so often met with indifference.

"I didn't imagine that my fear and that my pain would turn into impact," the musician said in accepting her trophy.

"I want to thank god for giving me the gift of a voice and a pen and using me as a vessel to create change," she continued.

"Remember, we are the change that we wish to see, and that fight that we had in us, the summer of 2020 - keep that same energy."

Prior to the 2021 gala, H.E.R. already had two Grammys under her belt.

Born Gabriella Wilson, the performer maintains an air of anonymity, often shielding herself behind bold, dark sunglasses and letting her velvety vocals speak for themselves.

The Californian - whose stage name is an acronym for "Having Everything Revealed" - was well-respected within the industry long before she broke into the mainstream.

She recently performed America The Beautiful during the Super Bowl pre-game show.