The 1975 Eagles song Don Henley says is the most difficult to sing: “My voice has to be just right”No one goes into an Eagles song looking to hear something too flashy. Even with a good melody, though, Don Henley admitted having trouble singing a handful of the group’s greatest efforts. We had Don Henley.” As JD Souther put it, “Don Henley could sing anything he wrapped his voice around. Although there were years of wear and tear on his voice, Henley’s subtle inaccuracies seem to be a time capsule of what Eagles songs mean to him.