John Frusciante’s career away from the Red Hot Chili Peppers has been wildly, even exhaustingly, ambitious — The Empyrean is his tenth solo album (and sixth since 2004). Unshackled again from the need to craft radio-ready riffs, the guitarist unfurls long-winded but beguiling keepers such as “Before the Beginning,” a bittersweet, serpentine instrumental. “God” nods to effervescent, Zombies-style ’60s pop, while he warbles in a charmingly fragile falsetto. But the highlight is set closer “After the Ending,” a wobbly, synth-drenched power ballad that showcases Frusciante’s knack for warping even the most hackneyed forms into intriguing new shapes.