Don't let the bookworm specs or aloof looks fool you, The Sheila Divine wants to kick your butt.

There are moments on the band's new compact disc, Where Have My Countrymen Gone,'' when the group, recently expanded to a quartet, unleashes howling squalls of guitar behind throat-shredding screams.

Such outbursts are usually contained between slices of heady, melodic pop right out of the Radiohead School of Songwriting.

In short, The Sheila Divine is a band not easily pegged but ultimately rewarding since it never lets diversity overrun pure song craft.

We set out to write better songs to show everyone that did not believe in the last record. We wanted to say, See what you're missing,' '' said Sheila Divine drummer Shawn Sears. If you're in a band, you have to be cocky. You've got to believe you're the best and you're going to make it. I honestly know we are a good band and have things going for us.''

FULLER THAN EVER

Listen to Where Have My Countrymen Gone,'' and it's hard to argue with Sears. It's a record that fires back at the most recent British Invasion using blood-warm lyrics and challenging musical arrangements rooted in strong, hook-flaunting pop melodies.

With the recent addition of guitarist Colin Decker, The Sheila Divine is sounding fuller than ever and remains a beacon of creativity on the Boston rock scene. Decker joined singer and guitarist Aaron Perrino, bass player Jim Gilbert and Sears in time to record Where Have My Countrymen Gone.''

The band celebrates the release of its new disc with a concert Saturday at The Lucky Dog Music Hall, 89 Green St., Worcester. The Curtain Society, Longwave and Reverse are also on the bill. Advance tickets are available at Strawberries record stores, online at tickets.com, or by telephone at (800) 477-6849.

The Sheila Divine formed in the mid-'90s when Perrino, Gilbert and Sears reconnected in Boston after having first met at the State University of New York in Oneonta. The Sheila Divine got noticed first by Cherrydisc Records in Boston, which helped record its eponymous EP. That project led to a deal in late 1997 with Roadrunner Records, a label The Sheila Divine left not long after the 1999 release of New Parade.'' The fit was not a comfortable one between the band and a record label that specializes in heavy metal.

The band gained additional notice in 1998 when it opened a handful of concert dates for singer Morrissey, whose old group, The Smiths, is clearly an influence upon The Sheila Divine.

To tour with Morrissey and win over those fans was big. Those are diehard fans, like Deadheads, and usually (they) don't care who is opening up,'' Sears recalled.

With the March 20 release of Where Have My Countrymen Gone,'' The Sheila Divine is back in the spotlight. The band now releases its music through Co-Op Pop, a new record label formed out of a partnership among Newbury Comics record stores and a few band managers, including Worcester native Michael Creamer, who manages The Sheila Divine. The label is currently working with Letters to Cleo singer Kay Hanley, Ellis Paul, The Push Stars and Orbit.

Creamer described Co-Op Pop as a collaborative effort that gives strong bands a way to make money while allowing them to concentrate on the making of the music.

The model is welcome by The Sheila Divine.

What really got us going was we didn't have a label anymore to push us in a certain direction. We started with this lofty idea of doing something like the Flaming Lips Soft Bulletin.' But we realized that's not us,'' Sears said, referring to one of the more experimental rock records of the past few years.

Where Have My Countrymen Gone'' is not short on verve, though. The opening track, Countrymen,'' is a sweeping piece of cinematic rock that touches on all the places the record eventually visits on the 10 other tracks. The heavy sigh of Antidote'' and Vanishing Act'' are familiar sounds from The Sheila Divine. But the crazed edge of Ostrich'' and Sideways'' are bruising new moves for the band, made possible by the additional guitarist. (It's loud, but not harsh, mind you.)

We could have done a whole album of Antidotes.' But Aaron has a need to do some songs where he just screams. We could not be a one-dimensional band doing all space ballads,'' Sears said.

Where Have My Countrymen Gone'' is not exactly a mirror of what the band is like live. Sears said there are nights when all it wants to do is space out, and others when nothing but the hard rockers make the set list.

Regardless of musical mood, the band tours as often as possible.

Our manager's philosophy is to tour, tour, tour until you're a headliner everywhere you go,'' Sears said.

According to Creamer, such a plan has made The Sheila Divine big in the Bs- Boston, Buffalo and, believe it or not, Belgium, where radio support is strong and live dates will be booked for the summer.

Closer to home, Boston rock radio outlets WBCN-FM (104.1) and WFNX-FM (101) have been spinning tunes from Where Have My Countrymen Gone.'' Sears said the disc was the third most added title to college radio stations when delivered to them a week before its commercial release.

Although The Sheila Divine may have to work twice as hard to get half as much attention as its peers on major record labels, Sears said the group is happy with the way things are going.

It's a lot nicer than sitting on your butt after getting dropped,'' he said.

The Sheila Divine

Where: The Lucky Dog Music Hall, 89 Green St., Worcester

When: 9 p.m. Saturday

How much: $8