It's not uncommon for new material -- demos, unreleased tracks and more -- to make its way out following a musician's death. Fortunately, Merle Haggard's family has access to plenty such recordings.

In an interview last spring, in support of his and Willie Nelson's Django and Jimmie album, Haggard revealed to Broadway's Electric Barnyard that he had "probably 300, 400 songs that I haven't released that I've collected over the years" stashed away.

"We call it 'the archive,' and we haven't released anything from that," Haggard explained. "When I get unable to record or sing anymore or get killed or something, well, they'll probably put it out."

Prior to Django and Jimmie, Haggard last released new music in October of 2011. That project, Working in Tennessee, earned a Top 30 spot on the Billboard country charts.

Following a bout of pneumonia, Haggard died on Wednesday (April 6), his 79th birthday. His funeral is set for Saturday (April 9) on his property in Palo Cedro, Calif. The country icon pre-planned the ceremony and asked that Marty Stuart, Connie SmithKris Kristofferson and Willie Nelson all attend and perform.

“He requested that Connie sing “Precious Memories,” that me and Connie sing his song “Silver Wings,” and that I officiate the service,” Stuart says. “We’re honored to do it.”

10 Essential Merle Haggard Lyrics