As speculated in this column last month, the keynote event of this year’s Chet Atkins’ Musician Days festival in Nashville will honor guitar greats Duane Eddy and Grady Martin and feature tribute performances by John Fogerty, Willie Nelson, Peter Frampton, Marty Stuart, Vince Gill, Bonnie Bramlett and others. Billed as “Witness History III: The Twang Years,” the April 5 concert at the Ryman Auditorium kicks off the four-day citywide musical festival. Chet Atkins’ Musician days, April 5 -8, will feature a series of concerts on various stages in or near the downtown Nashville area. The event also showcases various workshops led by prominent music masters. The festival raises money for educational programs such as the Chet Atkins Music Education Fund and the Country Music Hall of Fame’s Hands Across the Row initiative. Inaugurated in 1997, Chet Atkins’ Musician Days celebrates the musicians — like Atkins, Eddy and Martin — who have given Nashville its nickname of Music City.