The Crackerjacks are featured in a rock book, History of Memphis Bands, 1960-72 by Ron Hall, available at bookstores.
Besides Bobby Sowell, David Preola and Roy Yeager, other members included brothers Ricky and Micky Caughron and bass player Murphy Odom.
They were a popular band with area colleges and universities, traveling the Mid-South in Mississippi, Arkansas, Kentucky and Tennessee.
Eventually, Fred Prouty replaced Yearger on drums and occasionally, Bobby Whitlock also sang with them.
Whitlock went on to play keyboards with Derek and the Dominoes, Eric Clapton and the Beatles's George Harrison.