Wilco's 11th album, 2015's Star Wars, was a playful and angular set of noisy pop and pop-friendly noise, and it seemed fitting that it literally appeared out of nowhere, with the band sending it out as a free download without any advance warning one July afternoon.

Little more than a year later, Wilco has released a follow-up, Schmilco, and in many respects this album is the flip side to Star Wars.

Schmilco feels every bit as spontaneous as Star Wars (and much of the material was recorded during the same sessions), but where the earlier album seemed full of the joy of making music, this one is somber and low-key, a set of navel-gazing music even as the tunes confirm that Jeff Tweedy's way with a melody hasn't failed him.

Acoustic guitars dominate most of Schmilco's 12 songs, with Tweedy's vocals right up front, sounding introspective and emphatic at once.

On first listen, Schmilco plays like the work of one man and his guitar alone with his thoughts and his sorrows late one night.

It takes a couple of spins for the contributions of the rest of the band to really sink in, but once they do, it becomes apparent this truly is a Wilco album, as Nels Cline's guitars, Pat Sansone and Mikael Jorgensen's keyboards, and Glenn Kotche's drums bring a rich spectrum of dynamics and texture to the songs, while John Stirratt's bass anchors these songs both melodically and rhythmically.

Just as 1999's Summerteeth sounded like a smart pop album when observed casually but was an emotional horror show beneath the surface, Schmilco feels simple and declarative on first glance, but the deeper one is willing to dig, the more there is to find, both in terms of the band's interplay (which gets better and more intuitive with each album) and Tweedy's songs (which boast as much compassion and concern as brooding).

Star Wars was Wilco's cheerfully bent version of a summer album; Schmilco is clearly music for autumn, meant for cool nights, crunching through the leaves, and the occasional dark night of the soul.

And it speaks volumes about Wilco that they could make two albums so different within such a short space of time, and both times giving us music that sounds like no one else.