Bowling Green John Cephas and Harmonica Phil Wiggins wasted no time mapping out a musical tour at the Paint Branch Unitarian Church in Adelphi on Monday night. The renowned blues duo, together now for nearly a quarter-century, spent the evening commuting back and forth between the Mississippi Delta and the East Coast Piedmont region--a journey that shed abundant light on the development of rural blues.

From the legacy of the Delta, the pair extracted tunes by Robert Johnson and other artists that combined stark imagery with biting single-note guitar lines and mournful harmonica refrains. Cephas's resounding baritone never sounded more impassioned than when he was exploring this music; it clearly moves him in ways nothing else does. And Wiggins wasn't merely along for the ride. Blowing his harmonica in "cross-harp" fashion through cupped hands, he amplified the pain and despair vented by Cephas's voice and guitar.

In sharp contrast to the Delta's brooding laments, the Piedmont tunes were full of bouncy, ragtimey guitar patterns and a mixture of innocent, suggestive and exuberant lyrics. There were exceptions--a prison blues, for one--but for the most part the Piedmont music radiated an engaging spirit and energy, fueled by Cephas's infectious weave of regional guitar patterns and Wiggins's chugging harp rhythms and vibrant solos. Before the tour ended, rousing spirituals and party anthems filled the air, illustrating what Cephas called the duo's "blues for every occasion."