Paul McCartney met two of the women who helped inspire the Beatles’ White Album classic “Blackbird”backstage at his Little Rock, Arkansas concert Saturday night.

The women, Thelma Mothershed Wair and Elizabeth Eckford, were two members of the Little Rock Nine, a group of nine black students who faced discrimination and the lasting impact of segregation after enrolling in the all-white Little Rock Central High School in 1957, following the Supreme Court’s historic Brown vs. the Board of Education decision.

After the Little Rock Nine enrolled, Arkansas governor Orval Faubus protested their entrance into the school, which in turn sparked the Little Rock Crisis. It was these events that inspired a Paul to write the song “Blackbird.”

He tweeted, “Incredible to meet two of the Little Rock Nine— pioneers of the civil rights movement and inspiration for Blackbird.”

(h/t Rolling Stone)