Came blue: Bill Callahan at the Rock & Roll Hotel on Thursday.

Chris Richards: Callahan’s music has a stoic quality that, instead of sending you off to sleep, somehow heightens your awareness. You’re listening carefully for the sentiment, the humor, the secret punchline. He’s a physical performer in the same way — almost completely motionless, but occasionally erupting into these little Muhammad Ali flutter steps. The rest of the time, his weight is on his right leg as he keeps time with his left knee. Bob-bob-bob-bob. These aren’t sing-along songs, or clap-along songs, or even toe-tap-along songs. They’re knee-bobbing songs. And they’re the best knee-bobbing songs.

David Malitz: Despite all of the crowd shuffling that comes with standing at the back of a sold-out show, it’s still my preferred spot for Callahan. He’s someone who I just don't want to get too close to. Despite being continuously active for 20 years, he still has a mystique — not because he's cultivated it, but because he’s just a genuinely singular and isolated dude. From my spot next to the soundboard I couldn’t see his drummer or guitarist. It was just Callahan, torso and up, hovering above a sea of motionless heads while these spastic drum fills and scorching guitar leads occasionally shot into the mix as Callahan stared, strummed and sang. I stood still, closed my eyes and entered a meditative state that no amount of nudging or bumping could knock me out of.