The sounds of the space age in the intro that kicks off Secret Mezzanine’s Passing Dreams hint at a modernist ambition in the duo’s music, and the album’s track listing, with song titles like “Electron,” “Diode” and “First Derivative Rule,” suggest that there’s some physics/math geekery afoot as well. But the music of Cai Caudill and Rob Greene is anything but cold and high-tech. Instead, there’s a thread of easy traditionalism that runs throughout the album’s eight tracks. The foundation of the album is the duo’s guitar work, most often a spritely acoustic interplay that keeps the songs moving at a brisk clip. Those familiar with the duo’s covers know their fondness for the Black Keys, but here Secret Mezzanine forego that band’s trademark distortion and grit for a cleaner sound. Similarly, where the vocals on Passing Dreams are often reminiscent of a 90s-grunge-rock moan, they never slip down to that genre’s level of despair.

Instead, Secret Mezzanine often jump back a generation and dig up earlier influences, throwing in 60s-style wah-wah or reverb effects to create a vintage atmosphere that meshes nicely with their fresh song structures. That the duo can make their music seem so firmly aware of the 20th century while still featuring the occasional ukulele speaks to the versatility of their musicianship.