On some college campuses, a cappella groups have become as common as frat parties and writing seminars.

The phenomenon is almost exclusively collegiate -- most singers find that their glory days are bookended by their acceptance into the group and graduation -- which makes Straight No Chaser’s success all the more unusual.

The group is comprised entirely of former Indiana University students, all of whom sang in college before turning their undergrad hobby into a professional career.

What separates these guys from other vocal groups is the fact that they still sound like a college ensemble, right down to the vocal percussion and nonsense syllables that mimic the sound of real instruments.

That’s not meant to downplay their talent; all the members sing quite well on this album, with Michael Luginbill and Jerome Collins leading a strong pack of soloists.

In a genre that’s become increasingly dominated by studio enhancement (which, with the flick of a button, can transform a human voice into a snare drum or electric guitar), Straight No Chaser take a somewhat organic approach, relying less on the capabilities of the soundboard and more on the classic appeal of nuanced, textured arrangements.

As a result, With a Twist presents a sharper, mature version of the music these guys performed in school, with songs by Jason Mraz, Coldplay, and Oasis dotting the track list.

It’s also one of the biggest "real world" success stories of collegiate a cappella, an album that owes its existence to the campus but targets a larger set of listeners.