It's 1927, the jazz age, with poet Carl Sandburg toting a funny little guitar and strumming carelessly to the old tunes: "Whisky Johnny," "Where O Where Is Old Elijah?" The Galesburger/Chicagoan published his wildly popular American Song Bag with 280 songs from sailors, cowboys, railroad hands, pioneers, prisoners, and preachers. Sandburg, motivated by The People, Yes, finds democratic merit in these common songs.

When you look at publicity photos of the band on its Web site and elsewhere, stereotypes about hippies come to mind. There are rural settings, and some long hair, and some naughty bits - yes, a pair of breasts, pubic hair, and even a penis or two.

Describing the music that he's spent more than half of his 38 years learning to master, blues guitarist Nick Moss states, "There's a lot of nuance that people don't realize," and underscores his point with an unusual - but apt - analogy.

"To me it's like food," says Moss in a recent phone interview.

To understand the Degree of Difficulty inherent in the Nova Singers' season-opening concert, first imagine singing a particular vocal line - be it soprano, alto, tenor, or bass - against the three other vocal lines, and doing it a cappella, to boot.

Then imagine singing your part while those four parts turn into eight.

Then imagine singing your part while those eight parts turn into 12.

And then, imagine staying on your part with 81 people around you attempting the exact same thing.