Before Harold Arlin voiced the first Major League Baseball broadcast on August 5, 1921, the only way to experience a game was to go to the ballpark. The only way to follow scores was to look up at a wooden scoreboard to see them changed manually.

Legends have sat behind microphones and developed a rich tradition of baseball broadcasting ever since. Every big-league city has had its own play-by-play icon, with some becoming national figures: Vin Scully (Los Angeles Dodgers), Red Barber (Cincinnati Reds, Brooklyn Dodgers and New York Yankees), Mel Allen (New York Yankees), Harry Caray (Chicago Cubs), Harry Kalas (Philadelphia Phillies), and Jack and Joe Buck (St. Louis Cardinals).

But Arlin was the Wilbur Wright of baseball broadcasting. With no Orville doing color commentary, he sat behind a makeshift mic in the summer of 1921 and delivered the first radio play-by-play. His Kitty Hawk was a box seat behind home plate at Pittsburgh’s Forbes Field. His audience was a small group of shortwave radio enthusiasts who tuned into the Westinghouse Company's KDKA in Pittsburgh—the first commercial radio station in the United States.

A  25-year-old electrical engineer for Westinghouse, Arlin checked out the new radio setup out of curiosity, he told the Mansfield (Ohio) News-Journal in an interview in 1981. After hearing Arlin’s rich voice, the powers that be talked him into going on air.

Within a few years, Arlin was described by the Times of London as the “best-known American voice in England.” KDKA’s signal reached all the way across the Atlantic. That created a challenge for KDKA. With that kind of audience potential, the station needed to get creative with its programming.

The years after the end of World War I in 1918 unleashed a flood of talent and innovation onto the public airwaves. KDKA—Westinghouse’s in-house station—made history by broadcasting results from the 1920 presidential election. About five hundred listeners, a Pittsburgh newspaper later reported, learned that Warren G. Harding had defeated James Cox. There were five licensed radio stations in the United States in 1921. By 1924, there were more than 500.

But for a time, Arlin and KDKA had the field largely to themselves, and they attempted to plough as much of it as they could.

"Baseball," someone suggested.

"Too boring" was the response.

Nevertheless, the station decided to give it a try, a “one-off” broadcast just to see how it would go. Technicians concocted a microphone from a telephone–the “mushiphone” looked like a mushroom or a tomato can with a felt lining. KDKA distributed radios to employees’ friends and families, simply to create a potential audience.

The game that day was between the host Pittsburgh Pirates and the visiting Philadelphia Phillies. With mystified fans sitting around him in the stands, Arlin delivered a description of the game into his mushiphone.

Arlin had never listened to a baseball game on the radio. No one had. He couldn’t banter with some wisecracking color commentator. He had no commercials to break up the action. He didn’t give his name. He had no signature home run call.

“Let’s think about Harold Arlin and that first broadcast,” wrote Pat Hughes, longtime play-by-play man for the Chicago Cubs and a student of broadcast history. “Was he nervous? How much preparation did he do? How detailed was his description of the game, if at all? How often did he give the score? Did he even consider things like personality, humor, or style? Probably not.” No tape of the first broadcast exists, so no one knows.

The day after the Pirates’ 8-5 victory over the Phillies, Arlin broadcast a Davis Cup match between Great Britain and Australia in Pittsburgh—the first tennis event on radio. He relayed match information provided over the phone. Two months later, Arlin was the play-by-play voice for the first college football game broadcast on radio, a contest between West Virginia University and the University of Pittsburgh.

That year was a seminal one for radio—the first presidential inaugural address was broadcast as well as the first live boxing match, first weather report and first religious service.

Arlin became a regular on-air presence on KDKA, and was called the “world’s first radio disc jockey.” One day, he was interviewing Babe Ruth, who brought a prepared text to read. Ruth got nervous when the microphone was in front of him, so Arlin read his speech while Ruth smoked a cigar. Arlin later received letters commending Ruth for his polished speaking voice.

Arlin's broadcasting wasn’t always smooth. During his second college football broadcast, he got so excited when the University of Pittsburgh scored against Nebraska that he broke a piece of equipment. The station went silent. That happened again, only this time it was boxer Jack Dempsey, falling out of the ring and onto Arlin’s equipment.

Jack Dempsey. Babe Ruth. Football. Tennis. Baseball. After a few years and a number of broadcasting firsts, Arlin stepped away from the mic and moved to Mansfield, Ohio, taking on another role at Westinghouse. In Pittsburgh on August 30, 1972, he was called out of retirement to call an inning pitched by his grandson, Steve, of the San Diego Padres.

The Mansfield News-Journal reported that, as of 1981, Arlin—who died in Mansfield in 1986—still had the lineup cards from that 1921 Phillies-Pirates game. Quite by accident, the young electrical engineer had wandered into a radio booth and into broadcasting history.

Arlin invented sportscasting.

The world didn’t change immediately. Baseball teams were reluctant to broadcast games because of the fear fans would listen rather than go to the ballpark. The Sporting News even editorialized against games on radio in 1925: "Broadcasting stories of games as the games go along is the equivalent of a succotash party with neither corn nor beans." It wasn’t until 1939, 18 years after Arlin’s first flight, that all Major League Baseball teams had local broadcasts of their games. Games on radio became wildly popular.

“Harold Arlin was a pioneer,” Cubs voice Hughes wrote. “While his first attempt was probably a bit awkward, it did begin radio’s marriage to baseball, a match made in heaven that continues to thrive to this very day.”