Like many couples embarking on their second decade together, the Black Keys decided they needed to spend some time apart. Once Dan Auerbach and Patrick Carney wrapped their supporting tour for 2014's Turn Blue, the pair went their separate ways. During the next half-decade, neither musician laid low, busying themselves with production work and, in Auerbach's case, releasing two albums of new original material (Yours, Dreamily was the 2015 debut of his second band the Arcs, while 2017's Waiting on a Song was his second solo record). All of that extramarital wandering pays great dividends on Let's Rock, the duo's first album in five years. Lighter and leaner than Turn Blue -- and, ironically, considerably more colorful, too -- Let's Rock doesn't so much find the Black Keys trying new recipes as revisiting old favorites with fresh, elevated ingredients. Blues, garage, and old soul remain at the foundation of the group's sound, but they've swapped jammy excesses for over-saturated fuzz guitars and stacked vocal overdubs. Only two songs on Let's Rock threaten to break the four-minute mark: with its lava lamp psychedelic swirl, "Walk Across the Water" drifts for a luxurious length, while the brightly skipping "Get Yourself Together" gets there quicker. This concentrated brevity makes the album play a bit like a fantasy jukebox, spinning out hooks and harmonies with abandon. Sometimes, the Black Keys accentuate this pop undercurrent -- "Tell Me Lies" feels as if it's flirting with Fleetwood Mac's "Little Lies," "Sit Around and Miss You" glides down a gilded highway -- which helps give the album a dreamy weightlessness even if it's doused in layers of electric guitars. Scratch the production gloss a bit, and it's apparent those six strings are balanced by clever drum loops and other digital flair that give the album a modern vibrancy, even if its sensibility is unabashedly retro. Perhaps all these glowing, percolating sounds don't rock as hard and heavy as the earliest Black Keys album, but Let's Rock has an appealing ease to its execution. It's a good-time record designed for daylight and, after the murky Turn Blue and its ensuing hiatus, it's refreshing to hear the Black Keys step out of the dark and into the sunshine.