Back then, Rachel had just begun teaching herself to play the flute. Today she's composing elaborate pieces of music for Jazz ensembles, recording every track herself.
Pinto considers Rachel "super talented."
Rachel is much higher-functioning than Rex, but still, David says, she has similar problems connecting her music with stories or feelings.
"I asked her, 'Tell me some possible lyrics.' She had no idea," he says. "Any lyrics whatsoever.' Okay, so I said, 'Let's give a story about something that made you angry.' She couldn't."
"I said, 'Okay, play me something sad.' She couldn't. And that astounded me, to see how deep these kids go. But if you just move 10 degrees to the left, how shallow. They are fonts of wisdom and you're amazed. But move a little bit left, they don't have anything to say," Pinto adds.
Asked if he thinks it's possible for him to teach Rex and the other children to imitate emotion, Pinto tells Stahl, "Yes. And I think like all things, there's a hope that imitation will lead to understanding. "
So when Pinto has Rachel play Rex's new composition, he's trying to use the extraordinary musical bond they share to build something that does not come naturally: a simple friendship.
"It's still very hard for him to be friends. To have that deep connection," Rex's mom explains.
Cathleen hopes that music can help create a place for her son in the mainstream world, and it's already happening Rex leaves his special ed classroom every day for the school choir and band, and while he still can't fully relate to the other kids, with Rex, you never know when there's going to be a breakthrough, as Cathleen learned from David Pinto about something she'd given up on because of Rex's continuing aversion to touching things.
"I saw this twinkle between David and his wife. And, 'What's going on?' And he said, 'Well, we were gonna keep it as a surprise for you. But Rex is reading Braille,'" Cathleen remembers. "First I didn't believe it. I said, 'I'd like to see that. Now.'"
"And at that point, you know, to see the tears in her eyes. She was deeply moved," Pinto remembers of Cathleen witnessing this breakthrough.