A collection of home demos and live cuts, Acoustic demonstrates what we already know: John Lennon’s voice is a singularly expressive instrument; the only singer in his class is Dylan. Accompanied solely by his functional acoustic guitar on most of these lo-fi, post-Beatles recordings, Lennon’s candid vocals take on a primal intimacy—you know he means every word, whether he’s dealing with the mundane (“Watching the Wheels”) or the metaphysical (“Imagine,” “God”). More artifact than album, Acoustic is nonetheless gripping from moment to moment. By contrast, Rock ’n’ Roll, Lennon’s 1975 tribute to his early-rock influences, suffers from stock, overcooked arrangements and Lennon’s playful but emotionally noncommittal performances. If he and his cohorts had been more ambitious, Rock ’n’ Roll might’ve been a classic rather than a diversion. But even when he’s just throwing it away, Lennon has extraordinary presence, and taken on its own modest terms, the album possesses an undeniable charm.