As one-sentence rock-critic summations of chart-topping, arena-filling emo giant Death Cab for Cutie go, it always has been hard to top the line Summer tossed Seth back in the day on “The O.C.”: “It’s like one guitar and a whole lot of complaining.” No, it never was entirely true; for one thing, the Bellingham, Washington quartet makes good use of two guitars, especially on the fan-favorite epic of mope, “Transatlanticism” (2003). But on the group’s seventh album, that knock is less accurate than ever.

For starters, this clearly is guitarist/keyboardist/producer Chris Walla’s album, in terms of the ever-expanding musical palette (damn, these guys use grand piano well, amplifying the incredible vibe on “I Will Possess Your Heart” from 2008’s “Narrow Stairs”) and a marked devotion to swirling electronic textures as intense as the celebrated melancholy pop melodicism of his partner, band leader Ben Gibbard. Think of Coldplay upping the ante in that regard on the Brian Eno-produced “Viva la Vida,” but cooler (and it would be hard not to be). Gibbard has said that Eno’s ambient/art-pop classic “Another Green World” was the touchstone in the studio, but there are other nods to en vogue indie-rock heroes, too: Witness the driving Neu! drum beat that powers “Doors Unlocked and Open,” and the fact that for the first time, the band turned to an outside force to mix the record, the great Alan Moulder, tapped for his shoegazer past (Ride, My Bloody Valentine, Lush) more than his mainstream alt-rock credentials (Depeche Mode, Smashing Pumpkins, Interpol).

Just as significant, though, is a new and very welcome optimism from Gibbard, who all too often has made end-of-the-world prophet Harold Camping look like Little Miss Sunshine. Gibbard, who now has found his Summer as Mr. Zooey Deschanel, certainly has reason to be more upbeat about romance piercing the shadows these days: “Life is sweet/In the valley of the beast,” he sings on the album-closing “Stay Young, Go Dancing.” “And with her song/In your heart/It can never bring you down.” In context, this is a shift as radical as Slayer suddenly singing about Jesus or Ted Nugent praising PETA.

All of this is to say that Death Cab for Cutie has made its most enjoyable album. It’s not necessarily the group’s best, mind you, but the subtle soundscapes decorating the trademark melodies on songs such as “Portable Television,” “Home is a Fire,” and “Underneath the Sycamore” are in the end simply impossible to resist.

On the four-star scale: 3.5 STARS

STILL IN HEAVY ROTATION

Bewitched Hands, “Birds and Drums” (Look Mum No Hands)

Fleet Foxes, “Helplessness Blues” (Sub Pop)

Beastie Boys, “Hot Sauce Committee Part Two” (Capitol)

tUnE-yArDs, “WHOKILL” (4AD)

Gorillaz, “The Fall” (Virgin)

Clive Tanaka, “Jet Set Siempre No. 1”

The Feelies, “Here Before” (Bar None)

TV on the Radio, “Nine Types of Light” (Interscope)

Lykke Li, “Wounded Rhymes” (Atlantic)

Screeching Weasel, “First World Manifesto” (Fat Wreck Chords)

Lupe Fiasco, “Lasers” (Atlantic)

Lucinda Williams, “Blessed” (Lost Highway)

Radiohead, “The King of Limbs” (self-released)

Drive-By Truckers, “Go-Go Boots” (ATO)

North Mississippi Allstars, “Keys to the Kingdom” (Songs of the South)

Smith Westerns, “Dye It Blonde” (Fat Possum)

The Decemberists, “The King Is Dead” (Capitol)