Louis Armstrong is one of the most famous musicians who ever lived — he played trumpet like nobody before him, and he sang in a warm, gravelly voice you can name in about two seconds. Here is the strange part. For his entire life he celebrated his birthday on the wrong day, and not by a little either. He was off by a month and a year.

Armstrong always said he was born on July 4, 1900. Independence Day. It made a wonderful story — fireworks on his birthday, every single year, in every town in the country. He told it to reporters and he wrote it in his books, and since nobody had any reason to doubt him, nobody did.

Then, almost twenty years after he died in 1971, a researcher went digging through old church records in New Orleans and found the real answer tucked inside a baptism book. Louis Armstrong was born on August 4, 1901. He was a year younger than he believed, and his birthday sat a full month later than the one he had spent a lifetime celebrating.

Did he know all along? Probably not. Birth records for poor Black families in New Orleans in 1901 were often sloppy, or missing, or never written down at all, and Armstrong most likely grew up believing the July 4 story without ever thinking to question it. It was also, let's be honest, the better story. So it stuck for seventy years.

As a kid he collected nicknames about the size of his mouth. Gatemouth. Dippermouth. Satchelmouth, because a satchel is a bag. Then he visited Britain, where a magazine editor named Percy Brooks greeted him with a cheerful "Hello, Satchmo!" — having squashed Satchelmouth into a single word by accident. Armstrong liked it so much he kept it for life and had it stamped on his trumpets. Almost everybody else, meanwhile, he simply called "Pops."

On New Year's Eve in 1912, an eleven-year-old Louis fired a pistol into the air, got himself arrested, and was sent away to the Colored Waif's Home for Boys. That sounds like the end of a story. It was the start of one. A teacher there named Peter Davis put a cornet in his hands and taught him to play it properly, and within about a year Louis was leading the home's brass band.

Jump ahead to 1964. The Beatles were the biggest band on the planet, and they had owned the number one spot in America for fourteen weeks straight. Then a sixty-two-year-old jazz man bumped them off it with a show tune called "Hello, Dolly!" One trade magazine joked that all it took to break the Beatles was a song performed by an artist well into his sixties. Armstrong put it more kindly: "It's awful nice to be up there among all them Beatles."

Armstrong hauled a reel-to-reel tape recorder around in a steamer trunk, and he taped more than 650 reels of perfectly ordinary life with it: jokes, band practice, arguments, dinner, friends talking over each other. Then he went further. He decorated the boxes those tapes came in, snipping up photographs, telegrams and newspaper clippings and pasting them into homemade collages, roughly 500 boxes in all. He typed thousands of letters to fans, too, backstage and on trains, wherever he could find ten quiet minutes.

In 1967, Armstrong recorded "What a Wonderful World." The president of his American record label hated it so much that he had to be locked out of the studio during the session, and afterwards he refused to promote it. The song flopped in the United States. Britain adored it and sent it to number one instead. Americans finally caught up twenty years later, after it played in the film Good Morning, Vietnam.