A positive, let’s-try-anything spirit animates This Is All We Know, Number One Gun’s unexpected reunion project. After a stint with The Make, lead singer/guitarist Jeff Schneeweis reassembled the band’s original lineup for their first album together since 2006, funding the sessions through a Kickstarter campaign. Judging by the music here, these old friends enjoy each other’s company—there’s an easy chemistry in the punchy yet nuanced playing of these tracks. As frontman, Schneeweis retains the wide-eyed vulnerability that made NOG’s earlier releases so emotionally convincing. Upbeat effusions like “Get a Little Weird” and “Make This Last Forever” build on the band’s emo origins with sleek melody lines and kinetic arrangements. Guest vocal spots by Amberlin’s Stephen Christian (“Disappear”) and The Make’s Sarah Ann (“For You”) further boost the energy quotient. Wistful love songs like “Life in the Middle” and “Heartbeats” reflect both Schneeweis’ romantic idealism and the Christian faith that brought the group together in the first place. The gauzy textures of the atmospheric “I’m on Fire” close the album.