When the world becomes heavy and mankind appears to be struggling more than normal, many of us wish Fred Rogers were around to provide his distinctive comfort and serenity. For millions of Americans, Mister Rogers’ Neighborhood was more than simply an instructional show; it was—and continues to be—a wholesome example of true human decency and a hopeful reminder of what each of us is capable of becoming.

Mr. Rogers was adored for various reasons, one of which was his ability to recognize and celebrate each individual’s originality and ingenuity. He embodied this principle in even the smallest details that most people might overlook, like the piano section in his opening theme tune.

Rogers would sing, “It’s such a good feeling to know you’re alive…” at the start of each show, following a quick piano introduction. He followed the same basic routine throughout the theme song—set down what he was carrying, go to the closet, change from his suit jacket to his cardigan sweater, sit down to change his dress shoes to sneakers (always tossing a shoe from one hand to the other), and finish with “Please, won’t you be my neighbor?”

But we missed that the piano was played differently in each episode. For nearly three decades, Rogers performed the same performance with the same song (895 episodes in all), and each time the piano playing was distinct.

Rogers had hired world-renowned jazz pianist Johnny Costa to act as musical director for the program, and Costa performed the song live in the studio as Rogers sang to it. Costa was an improvisational talent, and while Rogers composed the music and lyrics for the show’s songs, including the theme song, he directed Costa to arrange and add his own touches to each one. And that was exactly what he did.

Costa collaborated with Rogers for 25 years, with his piano and jazz trio providing live musical accompaniment during each performance. Costa was responsible for the infrequent musical interjections while Mr. Rogers was speaking (until his death in 1996, when Michael Moricz took over), and most of them were improvised.

The bond between Rogers and Costa was nearly mystical.

Rogers recalled, “Music is essential to Johnny and me, and we communicate on an intuitive level that would be impossible without a sense for music.” “It is correct that there are no indications. We have a program rundown, of course, and he is familiar with my teleprompter material. But whether I’m working on a craft or whatever, he’ll always come in and emphasize an essential point.”

“I watch Fred, and there must be some kind of telepathy that we’re not aware of, because somehow I get the message to play or not to play,” Costa told me. “I’m sure that some of it has to do with working together all these years, but a lot of it is unexplainable.”

A YouTube artist known as Treehouse Detective told the tale of how the theme tune changed with each episode, sparking a surge of adoration for Mr. Rogers in the comments section:

“We really didn’t deserve Mr. Rogers. He gave him a melody and provided him the freedom to express his abilities and create masterpieces.”

“Yeah! This is gorgeous! And it goes much deeper than that! Mr. Rogers addressed each member of his audience as if they were on their way to becoming intelligent adults. That’s why he chose this God-level jazz musician to expose children to advanced and sophisticated musical expression.

“Costa also labored for nearly nothing. Mr. Rogers continually sought to pay it correctly, but Costa refused because he did not want the show’s restricted budget to go only to him.”

“Being mistreated as a youngster. I enjoyed watching Mr. Rogers. He was my sanctuary. As an adult, I felt extremely fortunate to be Mr. Rogers’ real-life neighbor. He was a very handsome dude. He’d sit and read the books he wrote for my daughter.” What a blessing.”

“Another amazing fact—he started describing everything on the show—what stuff looked like, what he was doing—very gently and casually because a little girl who was blind wrote to him and said she wished she could see what he was doing.”

“I sent Mr. Rogers three letters. He replied to all of his own correspondence, and each letter was meticulously typed, indicating that he had taken the time to read and react. A few years ago, my class was reading a book on Mr. Rogers. The kids didn’t know who he was, so I looked up an episode on YouTube. They were glued to it. Despite their very short attention spans, the person drew them into his community by speaking directly to them.”

No matter how much we learn about Mr. Rogers, he remains the best of us.