In the mid- to late 2000s, Nouvelle Vague's quirky mix of new wave and bossa nova was so popular that it became something of a cottage industry.

By the end of the decade, the group's discography included covers of songs from '80s movies (2008's Hollywood Mon Amour), collaborations with the artists whose songs they covered (2009's 3), and a collection of songs sung by their rotating cast of vocalists (2011's The Singers) with diminishing returns.

After an extended hiatus from recording, Nouvelle Vague reappears with I Could Be Happy, an album that attempts to remind listeners of the good old days and expand on the project's concept.

Marc Collin, Olivier Libaux, and company stretch their sound to include dream pop and punk covers as well as new wave, and, for the first time, perform original material.

The results are some of the group's best and worst moments.

I Could Be Happy opens with one of their finest covers yet, a version of the Cocteau Twins' "Athol-Brose" that surprises on many levels.

Covering a group as unique as the Cocteaus is risky, but Nouvelle Vague manage to translate the song's woozy gorgeousness into silky, subtle bossa nova that is a little more grounded yet still sublimely sensual.

Likewise, their version of "All Cats Are Grey" honors the mystique of the Cure's original while imbuing it with just enough playfulness.

More of Nouvelle Vague's mischief is on display with "Love Comes in Spurts," which gives Richard Hell & the Voidoids' brash punk a radical makeover along the lines of their reworking of the Dead Kennedys' "Too Drunk to Fuck." It's kitschy but fun, something that can't be said of the Nouvelle Vague-ification of the Ramones' "I Wanna Be Sedated," which only goes to show how fine the line between mischievous and ridiculous can be.

Elsewhere, the saccharine title track and a meandering version of Brian Eno's "No One Is Receiving" are disappointingly nondescript.

Nouvelle Vague fare better with their original songs: Collin's "Loneliness" and Libaux's "Maladroit" are pieces of pretty French pop that suggest that this musical tradition might serve the group best at this point.

Indeed, I Could Be Happy's covers vary so widely in quality that, in order to thrive, Nouvelle Vague may need to put their original concept aside for good.