By the time a band's eighth album rolls around, listeners usually know what to expect. One of the greatest attractions of Wilco is their continual ability to wrongfoot expectations. They straddle the span between rock and leftfield hard places with the surefootedness of mountain goats. Periodically muttered-about as one of America's best current bands, they are a recombinant six-piece anchored by singer Jeff Tweedy. Early albums were bittersweet primers in Americana, and the band can still inhabit those heartlands. Here, graceful "Black Moon" is a minor-key acoustic ramble, lapped by lap steel. But a more troubled mid-period allowed Wilco to be dubbed "the American Radiohead", thanks to an abrupt leap into leftfield. The pivotal Yankee Hotel Foxtrot (2002) remains their best-known album.

Since then, Tweedy has recovered from a prescription drug habit. Wilco's volatile line-up has stabilised, and their music has grown more elegant. Recent albums – Wilco and Sky Blue Sky – have brokered more resolutions than they have picked fights, prompting many Foxtrot–era fans to wonder whether Wilco have lost their edge. "It Dawned on Me", one of the breezier tracks here, does actually features a little whistling. Bits of Tweedy's vocals, meanwhile, track the structure of Supergrass's "Alright" alarmingly well.

Those seeking Wilconian wig-outs should start at the beginning. "The Art of Almost" kicks off this first release on Wilco's self-run label; the title could stand as a succinct description of what Wilco do. It's a restless seven-minute opener, pregnant with possibility, mustering uneasy beats, strings, and a Krautrock work-out in which gifted guitarist Nels Cline scrawls outside the lines with glee. At the other end of the album is "One Sunday Morning", an unobtrusively lovely 12-minute lop that offers a kaleidoscope of emotions surrounding a father's death, delivered in Tweedy's matter-of-fact rasp. We're ushered out with ticks, rustles, plinks and the merest wail of lap steel.

In between, Tweedy cleaves closest to the chipper end of his repertoire, contrary to his contrarian reputation. "I Might" is the sort of unabashed 1960s psych-pop that could teach MGMT a thing or two. "Sunloathe", meanwhile, lovingly channels the Beatles. Listen a little more closely, though, and "I Might" gives up a sample of the acerbic "TV Eye" by Iggy and the Stooges, while "Sunloathe" is hardly an idyll. The album's title isn't just soppy; it refers to a criminal's complete confession to the police. It's safe to assume Tweedy finds the polarisations that dog his band unhelpful. He had this to say in a recent interview about his maturing work: "The definition of growing up is being able to tolerate ambiguity. Not being able to tolerate ambiguity creates all kinds of problems for the world. It creates religious zealots... It's a scourge. Ambiguity is our world."

The Whole Love, then, is a nuanced, feel-good album full of open-endedness, laced with the kinds of observations only instruments can make fluently. It may not rank among Wilco's boldest works. It could have done with more wig-outs. But it captures the art of the almost with both hands.