For his dense, mellow second album, Ruban Nielson continues to challenge himself and his audience by working within the detailed sonic framework crafted on Unknown Mortal Orchestra's 2011 debut. Like on Nielson's first outing, the songs are a hodgepodge of collaged headphone candy, revolving around his childlike vocals, wonder, and multi-layered production, but here, lighthearted pop melodies are obscured by a melancholy tone. There are hooks, but they are not quite as obvious. This can be a good thing, however. Even if II is not as sunny, fun, or simple, Nielson wears the badge of maturity well and doesn't fall prey to typical sophomore pitfalls or lose track of his original psychedelic vision. It's reassuring to find that even after signing to Jagjaguwar, the album still feels like a bedroom studio creation, because his most endearing quality is his creative craftsmanship, and it shines. Each song is carefully and imaginatively put together, with nothing excessive to tarnish the clean lines of the songwriting or arrangements. This is especially impressive considering that on this album, Unknown Mortal Orchestra use a wider spread of sounds, and additional instrumentation is added by members of the touring band. Hip-hop breakbeats acted as the backbone for nearly all of the early material, so adding live drums changes the dynamic, but never seems to complicate matters. Instead, it provides a sense of movement that allows Nielson to show off his guitar playing, which is never showy but is extremely clever; rotating from apt funk riffs, to prog scales, to fingerpicking. From the opening moments of the trippy, lo-fi intro "From the Sun" all the way to the funky-as-a-Hendrix-ballad closer "Secret Xtians," II takes risks and achieves greatness.