Contemporary gospel's preeminent group, the Mighty Clouds of Joy carried the torch for the traditional quartet vocal style throughout an era dominated by solo acts and choirs; pioneering a distinctively funky sound that over time gained grudging acceptance even among purists, they pushed spiritual music in new and unexpected directions, even scoring a major disco hit. The Mighty Clouds of Joy were formed in Los Angeles during the '50s by schoolmates Joe Ligon and Johnny Martin; while still in their teens, the original group -- which also included Leon Polk, Richard Wallace, an...