Even the most devout atheists will be moved to shout "Amen!" by this rousing gospel album. It honors the 75th (diamond) anniversary of the Hummingbirds, the choral group organized in Greenville, S.C., by James B. Davis, then 12. Davis himself is now lead singer emeritus, but Ira Tucker Sr., who joined the group in 1938, when he was 13, now fronts the 'Birds with grace, style and a still-vigorous baritone with shades of Johnny Cash. William Bright's wailing lead on "Too Many Troubles" is a lesson in how Christian music influenced the blues and ultimately all of American music. Other highlights include "God's Radar," a high-tech gospel song whose zydeco arrangement provides a showcase for Garth Hudson's accordion, and the Grateful Dead farewell song "I Bid You Goodnight." The 'Birds don't need a lot of frills to get their message across. If nothing else, their time-tested style is a tribute to the virtues of directness and clarity.