The R&B vocal group had the desert fest crowd swaying to their 1994 chart-topping hit During his headlining set at Stagecoach on Friday, Cody Johnson began to sing a cover of “On Bended Knee,” the 1994 hit song by Boyz II Men for the Motown label. As he launched into the lovelorn song, the Philly soul greats appeared alongside the country singer as the crowd erupted in cheers of nostalgia. Nathan Morris, Wanyá Morris, and Shawn Stockman joined on stage and got the massive crowd swaying to the ballad. The group recently made a surprise appearance at another crossover-event, performing at the 20th anniversary concert of Nashville’s songwriters haven the Listening Room last month. Boyz II Men joined Brett Young, who offered, “In Case You Didn’t Know,” for the occasion. Earlier this month, Johnson announced his 10th studio album, Banks Of The Trinity , due June 26. “On this album, I wanted to tell the story about my childhood,” Johnson said in a statement .…