On their fourth album, A Crow Left of the Murder, Incubus got heavier, both musically and lyrically, which might have developed their music but it shrank their audience.

It's hard not to see their 2006 follow-up, Light Grenades, as a reaction to this situation -- not that they shrink away from the progression of Crow, but they polish and streamline their innovations from that album, resulting in a record that's sharper, cleaner, and more immediate in every respect.

This naturally means that Incubus doesn't sound as heavy as they did earlier in their career, but they're still pretty somber here; even when the rhythms crash and the guitars wail, this is serious music, but they have a lighter touch here than they did on Crow.

They also have a greater mastery of mood, as well as a greater musical variety than they displayed on the outset of their career.

Often, they use trippy, vaguely psychedelic soundscapes to set a tone that they later blast apart with tightly focused blasts of fury, such as the skittering "Anna Molly" or the intense two-minute ballast of the title track -- or even how the acoustic introspection of "Earth to Bella" is ripped apart by shards of noise, not unlike Radiohead's "Creep." Radiohead comes to mind a few times on Light Grenades, largely in how Incubus uses echoed guitars on their expansive mood pieces, but more often they sound like a leaner, hungrier latter-day Pearl Jam in their sense of purpose and dedication to serious rock.

Perhaps that's why "Diamonds and Coal" stands out so strongly in the latter half of the record: it's a tightly constructed pop song, their catchiest ever, that's unlike anything else on the record in its hookiness, which makes it all the more impressive.

And instead of suggesting that the rest of the record is lacking in hooks, it actually points out how Incubus has grown: that they not only feel comfortable releasing a piece of alt-pop as catchy as this, but they don't emphasize it, they merely present it as another dimension to their sound, just like how the delicate acoustic-driven "Paper Shoes" also sounds unlike the rest of the album yet still fits comfortably into the record's tapestry.

These moments of lightness illustrate the confidence Incubus now has and their increasing musical dexterity too.

On Light Grenades, they are a tightly focused, purposeful band, shifting moods and textures at the drop of a dime, proving that they have become a rare thing: a modern heavy rock band that actually grows and improves with each album.