An A-list group of artists—including Willie Nelson, Kacey Musgraves, Alison Krauss, Kris Kristofferson, Brad Paisley and more—have been tapped to record songs curated from Johnny Cash’s poetry, lyrics and letters. The new 16-song album, Johnny Cash: Forever Words, will be released on April 6. When Johnny Cash and June Carter Cash died in 2003, they…