When the invasion of Ukraine began, singer Andriy Khlyvnyuk cut his U.S. tour short, returned home and took up arms to defend his homeland.

A few days later, the Boombox singer posted a clip on Instagram that showed him in military fatigues, a New York Yankees baseball cap and a rifle performing "The Red Viburnum In The Meadow," a Ukrainian protest song written during World War I.

"A little motivation from the leader of the group 'Boombox' Andriy Khlyvnyuk," he wrote.

Now, rock legends Pink Floyd have taken Khlyvnyuk's vocals and composed a charity single around it — the band's first new original music since 1994's "Division Bell."

The track, "Hey Hey Rise Up," features 90 seconds of David Gilmour's string-bending solo, and Floyd drummer Nick Mason. (Needless to say, estranged bassist Roger Waters is noticeably absent.)

The title references the last line of the protest song: "Hey hey, rise up and rejoice."

How the song came about

"We, like so many, have been feeling the fury and the frustration of this vile act of an independent, peaceful democratic country being invaded and having its people murdered by one of the world's major powers," Gilmour, who has a Ukrainian daughter-in-law and grandchildren, said in a statement on the band's website.

"Then I saw this incredible video on Instagram, where he stands in a square in Kyiv with this beautiful gold-domed church and sings in the silence of a city with no traffic or background noise because of the war," the statement added. "It was a powerful moment that made me want to put it to music."

Gilmour said he spoke to Khlyvnyuk, who is recovering from a shrapnel injury, and played him a snippet.

"He gave me his blessing," Gilmour said.

The proceeds from the single will go to Ukrainian humanitarian relief, the band said.

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