Steph Curry has range both on the court and off it -- 'cause the NBA superstar was hitting the high notes during Benson Boone's BottleRock set over the weekend!!
Video of the Golden State Warriors guard's jam session at the music festival in Napa Valley made rounds recently ... showing the four-time NBA champion documenting the singer's passionate rendition of his viral track, "Beautiful Things," on his phone -- all while crooning along!!
It looked like Curry was having an absolute blast .