But one night last spring, Diffie stayed on the line longer than usual. When his girlfriend Liz Allison looked over at him, she knew it was no ordinary phone call. "Tears just started rolling out of Joe's eyes," recalls Liz. When he hung up, she found out why: Tyler, who has Down syndrome and cannot speak, had, for the first time, responded to Joe's voice on the phone. "He made noises at me," says Diffie. "It's a small thing, but it was such a breakthrough for him."
In fact, Diffie says, that moment reflected a breakthrough for himself as well. When Tyler was born in 1989, Diffie, then married to Tyler's mother, Debbie, was so overcome with anger and embarrassment over his son's affliction that for two days he wouldn't even call his parents back home in Velma, Okla., to tell them they had a grandchild. "I was just devastated," he recalls. "I remember thinking, 'How could I have something imperfect?' I was just so hurt. I heard Down's and thought the world had ended."
But in the years since, Diffie has come a long way toward understanding that it did not. He has learned not only to cherish his son but to accept both Tyler's achievements and limitations as part of who he is. "You're proud of all your kids," says Diffie, who also has two children, Parker, 13, and Kara, 9, from a first marriage, "but with Tyler it's special because any small thing he does is like a giant step. He learns so slowly, so anything he does, it's like, 'Wow, look what Tyler's doing!' "
Not that the wisdom came easily. In the first few weeks of Tyler's life, Diffie was more focused on assigning responsibility for Tyler's condition than in comprehending it. (Down syndrome is a congenital disorder caused by a chromosomal abnormality that results in mental retardation.) "I blamed Debbie, I blamed God, I blamed myself," says the singer. He credits his producer-manager, Johnny Slate, whose son, David, 12, has cerebral palsy, with pushing him forward. "He told me to quit feeling sorry for myself. He said, 'Let me tell you, that child right there will give you more joy than all your other children combined,' and it's true."
Still, the heartaches have been many. Plagued by sinus problems, Tyler underwent surgery in 1991 to remove his tonsils and nearly died when he asphyxiated. "He was in intensive care for seven or eight days, with all these bandages on him and tubes sticking in every portal," Diffie says. "We almost lost him."
Making things more difficult, Diffie had to rejoin his band on tour while Tyler was still in the hospital. "I didn't want to leave, and Debbie didn't want me to leave, but there were people depending on me," he says. "Eventually I had to go, not knowing if he would be there when I came back."
Happily, Tyler survived, although he seems to have lost the ability to speak as a result of the experience. "Before the surgery he had a small vocabulary—he was saying ball and Da-Da—but he hasn't spoken since," says Diffie, who now communicates with his son through simple sign language. Even then, Tyler doesn't always use the signs. "You don't know if it's out of laziness or headstrongness or he's just forgotten it. It's frustrating."
Equally stressful are the ordinary upsets: When agitated, Tyler has a tendency to bite and throw tantrums; he has to be monitored while he eats, to make sure he doesn't choke; and, at 5, he is still not toilet trained. But helping to ease the frustration are the letters Diffie now gets from fans—many of whom also have children with Down syndrome. "Some people write to say thanks for talking about Tyler, for being so open about it," Diffie says. "Some people say, 'Hey, man, we know what you're going through. Hang in there. Just love your kid, and it will work out.' "
Children with Down syndrome frequently attend Diffie concerts. "I think parents think, 'Well, if I take my kids to this guy's show, it's not going to be an embarrassment, because he has a child like mine.' "
Since his split with Debbie last year (the divorce was settled in August), Diffie has worked to integrate Tyler and Drew with Liz's children, Krista, 5, and Robbie, 3, from her marriage to the late NASCAR driver Davey Allison. (Allison died following a helicopter crash in July 1993.) Diffie tore out a bunk on his bus to create a carpeted play area, with TV and VCR, for when the youngsters hit the road with him. "The kids accept Tyler as another kid," Diffie says. "And Liz does great with him. We're like The Brady Bunch."
Although Diffie hopes Tyler will regain the ability to speak and will one day be able to hold a job and have his own home, for now he's happy with every step that Tyler takes. "Tyler's a beautiful child," he says. "I couldn't be prouder."