Considering that Cass McCombs’ two albums released this year – April’s Wit’s End and, his latest, Humor Risk – are both comedy-related puns, you’d expect his songs to be funny, or at least cheery. But it might be that the real joke is the incongruity between McCombs’ winky album titles and the beguiling bleakness of the albums themselves. On Wit’s End, McCombs established himself as a worthy successor to dreary balladeers like Leonard Cohen and Elliott Smith. On Humor Risk, his sound often takes on a sinister edge, as if that dreariness has manifested itself into a full-fledged psychopathic streak.

Humor Risk plants its roots firmly in the heartland rock tradition, but like Kurt Vile’s Smoke Ring for My Halo, it’s a pretty oblique take on the genre, full of quiet menace and near-psychedelic trappings. Opener “Love Thine Enemy” sets the tone: “Love thine enemy / But hate their lack of sincerity”, mutters McCombs with theatrical, self-righteous vitriol while the chugging Bob Seger power chords devolve into ambient chaos. On the upbeat epic “Mystery Mail”, McCombs pairs Skynyrd-esque guitars with a rambling narrative about two meth cookers and their separate paths to jail. The point is, McCombs always finds a way to subvert the heartland formula just enough to keep it fresh.

On the occasions when he hews a bit closer to the affable shoegazer persona he cultivated on Wit’s End, McCombs still manages to evoke a certain sense of dread. That feel is front-and-center on the Baudelaire-referencing “To Every Man His Chimera”, with its dripping guitars and McCombs gnawing on lines like “California makes me sick / Like trying, with a rattlesnake, your teeth to pick”. Even on the angular garage-rocker “Meet Me at the Mannequin Gallery” and the quietly beatific “The Living Word”, there’s a sort of unsettledness that peeks through the cracks of McCombs’ even-tempered singer-songwriter routine. The latter would be right at home on an easy listening station, if it weren’t for McCombs’ delivery and the strange suspension that happens at the end of every bridge.

And in the end, those little tweaks are what make Humor Risk such a memorable listening experience. It’s not that Humor Risk is even more dire than Wit’s End – that’s certainly not true, as anyone who’s heard the likes of “County Line” can attest. In fact, in many ways, Humor Risk is pretty light-hearted. But imagine you’re in your car with the windows down, humming along to a feel-good jam, and suddenly through your soft focus pierces a pair of lines: “I heard Daniel was stabbed with a ballpoint pen / About sixty times, by his cellmate Charles”. It’s humor, certainly, but it’s a wryly dark variety, to be sure.

In 2010, one of my favourite albums was Pope Killdragon by the tragically underrated Strand of Oaks, a collection whose best song, the unexpectedly moving “Daniel’s Blues”, is a revenge fantasy in which Dan Aykroyd hunts down the late John Belushi’s drug dealer. Cass McCombs is operating along the same continuum, if not necessarily on the same point of that continuum. The results are sometimes funny, sometimes scary, sometimes touching, but rarely boring.

• Multiple songs MySpace