The legendary singer Beyoncé wowed audiences of the MTV Video Music Awards on Sunday, performing a 15-minute medley of songs from her album “Lemonade.” Beyoncé invited to the gala several mothers of African-American men killed by police or vigilantes, including Wanda Johnson, mother of Oscar Grant; Lesley McSpadden, mother of Michael Brown; Gwen Carr, mother of Eric Garner; and Sybrina Fulton, mother of Trayvon Martin. McSpadden and Fulton appeared in the video for Beyoncé’s song “Freedom” holding pictures of their deceased sons.