Country singer-songwriter Willie Nelson appears at the Country Music Association Awards in Nashville, Tenn., Sept. 29, 1993. (AP Photo/Mark Humphrey)
Country music legend Willie Nelson on NBC's "Today" show in New York before his eightieth birthday. (Photo by Charles Sykes/Invision/AP, file)
Country singer Willie Nelson, center, and his wife Annie mingle with rock and roll guitarist Edgar Winter at the premiere of the film "Wag the Dog," Wednesday, Dec. 17, 1997. (AP Photo/Chris Pizzello)
President Clinton and first lady Hillary Rodham Clinton applaud Willie Nelson at the White House on Sunday, Dec. 6,1998, during a reception for Kennedy Center Award winners. (AP Photo/Ron Edmonds)
Willie Nelson listens to Kit Fogle, legistative director of the Ohio Farmers Union as he talks about livestock operations Wedensday, Aug. 12, 1998, in Columbus, Ohio. (AP Photo/Terry Gilliam)
Singers Willie Nelson and Lyle Lovett, right, perform with Lovett's Large Band at the annual ESPY awards show at New York's Radio City Music Hall, on February 13, 1995. (AP Photo/Ron Frehm)
Country singer Willie Nelson performs as the closing act at the US Festival in Devore, Ca., Saturday night, June 5, 1983. (AP Photo/Michael Tweed)
Country music singer Willie Nelson poses with President Carterâs son Chip at a fund raiser in Atlanta at night on Tuesday, April 15, 1980. (AP Photo/Nancy Magiafico)
Willie Nelson poses in a hotel in New York, Jan. 14, 2002. (AP Photo/Gino Domenico)
Country music singer Willie Nelson and his children Amy, left, and Paula talk with first lady Rosalynn Carter at the White House on Sept. 23, 1978. (AP Photo)
Willie Nelson poses with his wife, Connie, after receiving the Lifetime Achievement Award at the Songwriter's Hall of Fame Awards ceremony on March 7, 1983. (AP Photo)
Musician Willie Nelson performs during the Farm Aid Concert event Sunday, Oct. 4, 2009, in St. Louis. (AP Photo/Kyle Ericson)
Ke$ha and Willie Nelson appear on NBC's "Today" show on Tuesday, Nov. 20, 2012 in New York. (Photo by Charles Sykes/Invision/AP)
Willie Nelson performs at the Heartbreaker Banquet on Thursday, March 19, 2015, in Spicewood, TX. (Rich Fury/Invision/AP)
Country and Western singer Willie Nelson is appearing, Jan. 16, 1978 at the Rainbow Room in Rockefeller Center in New York. (AP Photo/RF)
Willie Nelson performs in concert at The Grand Opera on Wednesday, Sept. 10, 2014, in Wilmington, Del. (Owen Sweeney/Invision/AP)
Country singer Willie Nelson is seen in 1986. (AP)
Country singer Willie Nelson attends a reception for the recipients of the 2010 Kennedy Center Honors in East Room of the White House, Sunday, Dec. 5, 2010. (AP Photo/Manuel Balce Ceneta)
Country Singer Willie Nelson joined folk and rock singer Bob Dylan, right, on stage before more than 78,000 people attending the Farm Aid benefit concert. (AP)
Willie Nelson performs during the Farm Aid 2013 concert at Saratoga Performing Arts Center in Saratoga Springs, N.Y., Saturday, Sept. 21, 2013. (AP Photo/Hans Pennink)
Willie Nelson performs during the Farm Aid 2012 concert at Hersheypark Stadium in Hershey, Pa., Saturday, Sept. 22, 2012. (AP Photo/Jacqueline Larma)
Willie Nelson crosses the finish line at the first annual Willie Nelson distance classic on Sunday, June 15, 1980 near Lake Travis in Austin, Texas. (AP Photo/Daemmrich)
Country singer Willie Nelson performs during the pregame show before Super Bowl XXXVIII on Sunday, Feb. 1, 2004, at Reliant Stadium in Houston. (AP Photo/Dave Martin)
Willie Nelson and Farm Aid executive director Carolyn Mugar talk with reporters during a press conference prior to the start of the Farm Aid 2013 concert, Saturday, Sept. 21, 2013. (AP)
Willie Nelson arrives at the 56th annual GRAMMY Awards at Staples Center on Sunday, Jan. 26, 2014, in Los Angeles. (Photo by Jordan Strauss/Invision/AP)
Willie Nelson and Neil Young meet with members of the Senate Agriculture Committee on September 20, 1985 in an attempt to lobby for legislation that would boost farm income. (AP Photo/Scott Stewart)
Willie Nelson performs during opening set at the FarmAid benefit concert September 22, 1985 at Champaign, Illinois. (AP Photo/Mark Elias)
Singer Willie Nelson joins Texans United to protest a trade agreement, at an economic summit in Houston, Texas, on July 2, 1990. (AP Photo/Jim Johnson)
Singer Willie Nelson leaves the Federal Building in Austin, Texas, on February 3, 1993, after settling his tax problems with the Internal Revenue Service. (AP Photo/David Breslauer)