One of the few true shocks in rock music is when a young band with a seemingly short shelf life manages to transform itself into a cohesive, enduring, and artistically diverse outfit.

Take Silverchair, whose plodding angst anthems were the subject of much ridicule during the group's initial splash.

But they somehow kept going and kept improving, and Diorama is the sound of a band finally growing into their own skin.

These songs have a sense of space and tunefulness that was always missing from the band's previous efforts, and the production (by David Bottrill, with orchestrations courtesy of Van Dyke Parks) brings to mind everything from the charging anthems of Big Country to U2's first experiments with Brian Eno.

Singer Daniel Johns steps into the forefront here, showcasing his rich voice and shockingly catchy, twisting tunes with melodies that are hardly predictable but often delightful.

His efforts recall deceased singer/songwriter Josh Clayton-Felt, as they utilize a similar vocal approach and channel the same sort of psychedelic soul on tracks like "Tuna in the Brine." A song like "World Upon Your Shoulders" sounds utterly unlike the post-grunge efforts of Johns' earlier work, but in one song he takes the washed-out symphonies of Soft Bulletin-era Flaming Lips and the delicate falsetto pop of Jeff Buckley and combines them into a digestible pop nugget.

The solid guitar work from Johns also shows growth, as the songs often drift into Edge-like noodling that compliments his voice much more than the chugging riffs of their first few albums.

"Without You"'s Goo Goo Dolls-lite is an unwelcome twist, taking their newfound sense of melody and giving it a blustery chorus that robs the track of its power.

The thick "One Way Mule" is another minor disappointment, reverting back to Silverchair's grunge sound for a song that has little of the intelligence and beauty of the rest of the album.

But mostly this is a wonderful surprise from a band thought to have been finished in the late '90s.

Being hesitant to give this a chance is perfectly understandable, but Silverchair has grown up and put together a fine mix of orchestral pop and rock on Diorama.