Chris Smither heard Lightnin’ Hopkins when he was 17, and a life in music was jump-started. Smither is a blues revivalist, guitarist, and singer/songwriter. He’s been a mainstay of the festival, coffee house, and club circuits around the U.S., Canada, and Europe since his performing career began in Boston in the spring of ‘66. With a dozen releases to his name and over 35 years of performing and recording, Smither’s latest Leave the Light On is an example of his consistent excellence. Smither performed live in Studio 1A on Music with Jay Trachtenberg before his show at the Cactus Cafe Thursday night.