At the Verizon Wireless Amphitheatre box office before the triple threat concert of Bob Dylan, Willie Nelson and John Mellencamp, a sign noted that the two big screens on the side of the main stage would not be used.

Vanity? Age? It was probably 68-year-old Dylan’s request since he wasn’t allowing professional photos either.

But fans didn’t come to stare at Dylan’s jowls or Nelson’s crow’s feet. They came for the music.

Nelson opened the evening just after 6 p.m. before a giant Texas flag. Already, a vast majority of the crowd was in their seats. With only an hour, he squeezed in about 20 songs, wasting no time on small talk, save for a stray “thank you.”

The audience sang along to the classics such as the always rollicking “On the Road Again,” the enduring “Crazy,” and the still beautiful “Always on My Mind.” Naturally, the crowd vibed on his take of “Georgia on My Mind.” His backing band kept things spare; his drummer used a single snare drum. The focal was always on his voice and at age 76, he is still the master of that domain.

The highest energy portion of the night went to John Mellencamp, a relative baby compared to Nelson and Dylan at age 57. He danced and jumped about the stage as if he were still that rebellious 31 year old singing “Authority Song.” (”I fight authority but authority always wins…”)

He did slow down for a three-song acoustic set in the middle of his 70 minutes/ “How many of you want to hear a new song?” he asked. About 20 percent of the crowd raised their hands. “How many want to hear an old song?” he said. The rest of the audience cheered.

He gave a sly smile and said, “I have the deciding vote,” before breaking into a bit of both.

First up was his nostalgic 1987 hit “Cherry Bomb.” “That’s the old tune,” he said. Then he explained he had a new song, conceived in Savannah, recorded in Memphis on Monday, a wistful ditty called “Take Some Time to Dream.” The reception: very good. He then broke into one of his most popular songs still heard on soft rock stations nationwide, the 1985 classic “Small Town.”

Dylan, in his signature black hat, ended the night. His band shellacked his tunes with a bluesy, rock-a-billy sheen. His voice? At age 69, he’s as raspy and incomprehensible as ever. And in his classic “just the tunes, man” approach, Dylan made not a single comment to the crowd.

But his rapt fans couldn’t care less, cheering and dancing, especially during the hits such as “Workingman’s Blues #2,” “Highway 61 Revisited” and naturally, “Like a Rolling Stone.”