David Longstreth — the songwriter behind Dirty Projectors — is a man who’s rapturously in love for most of his eighth studio album, “Lamp Lit Prose.” Within the Dirty Projectors catalog, this is the joyful rebound from the bitter breakup songs of “Dirty Projectors,” the album he released in February 2017. But it also faces a bigger question: How should an artist respond to what America has become?

In Mr. Longstreth’s 15 years of releasing Dirty Projectors albums, “Lamp Lit Prose” is his shiniest, airiest, even catchiest set of songs. The new record exchanges the jarring, glitchy electronic intrusions and arid trap percussion he used on “Dirty Projectors” for the springy guitar lines of older Dirty Projectors albums, bringing out their warmest tones. The album’s palette also features a horn section, summoning R&B punch and jazz richness, powered by human breath.

Mr. Longstreth is still the classically trained musical oddball he was when he released “The Glad Fact” back in 2003. He still devises songs with melodies that hop around all over the place, meshed with precisely picked guitar counterpoint that also ricochets across the stereo channels. Yet amid the fractures and complexities, Mr. Longstreth also provides nuggets of approachable melody. And in new songs like “Blue Bird,” without second thoughts or any glimmer of irony or skepticism, Mr. Longstreth sings, “You and me, me and you/Something deep, something true.”