RIFF photographers’ best work in 2021 included these shots of (clockwise from top left) Lil Baby, Lindsey Stirling, J Balvin, Murs, Black Veil Brides, Tinashe, Bleachers, MisterWives, J. Cole, Korn, Megan Thee Stallion and KISS. Concerts returned, first tentatively and then in full force. We asked our photographers to…