Traditions die hard at Fenway Park. Two generations ago, every major league ballpark had an organ. Now considered outdated, many have been replaced by DJ's and recorded music. But at Fenway, the organ — used in conjunction with social media — keeps music up-to-the-minute. And fans get a say in what’s heard.

In 2003, when Josh Kantor was hired as organist for the Boston Red Sox, the job was like that of other ballpark organists: he played the occasional flourish, made musical commentary on the game, and accompanied the seventh inning stretch.

But about eight years ago, Kantor realized he could interact with fans live during the game and solicit requests for songs they’d like to hear.

Welcome, Twitter.

“This morning I got a request for a song called "Medicine for Melancholy," by Rivers Cuomo,” Kantor said, sitting at the organ as a recent game got underway. “During batting practice, I got a request for ‘Detroit Rock City,’ by Kiss, and a request for anything Springsteen.”

The Fenway Park organ sits on a podium in the corner of a noisy restaurant with a bird’s eye view the field. Surrounded by screens, speakers and a countdown clock, Kantor wore a headset for communication with the DJ and production crew. He monitored his Twitter feed through a laptop on his bench.

He decided to tackle “Medicine for Melancholy.” The request came from a person he hears from every once in a while.

“He’s a huge fan of the band Weezer,” Kantor said. “He always requests it.”

Kantor usually needles the fan before granting the request: “The last time I told him, ‘You’re gonna have to come up with something else. You have to show me you’ve heard of another band,'" he said. "So he sent this request.”

Kantor was amused, but he is nobody’s fool.

“He found a loophole in two ways,” Kantor explained. “He requested a song from a solo record of the Weezer singer. And he tugged at my heartstrings by telling me he’s at the game with his wife and it’s their first anniversary, and this is a song to which they entered their wedding reception a year ago. So I have to play it, but I can tease him about trying to trick me.”

If Kantor doesn’t know a song, he’ll pull up a stream on YouTube.

“I’ll give it a listen, just kind of pick along as I listen. I usually try to get the melody and bass first, then figure out what goes in the middle, in terms of chords and accompaniment,” he said.

Two listens, a little practice — he may create a cheat sheet with chord changes — and he’s good to go. And if he's going to grant a request, he gives the requester a heads-up. Before he did that, people would often miss it, he said. They’d be distracted or in the bathroom or on line for a hotdog.

The requests span songs from the 20th and 21st centuries, and just about every genre. Every game is different, but Kantor guesses that on average, he gets 20 requests per game. Of requested songs, he estimates that 20 percent he knows, 50 percent he knows somewhat, and the rest are entirely unfamiliar.

Kantor said he was skeptical of Twitter at first, and he took requests as an experiment. But it’s slowly snowballed to the point where virtually every song he plays has been requested by someone at the game. Last season, he fulfilled 749 unique requests, and at the end of the season, he published the list of those songs on his Twitter feed.

Back at the game, the requests trickled in: Someone asked for “I Want It That Way,” by the Backstreet Boys. And someone else requested “To Live and Die in LA” by Tupac, which Kantor said he’d never done before, “but it’s got a real nice melodic chorus that could work well,” he said.

Most requests are for a specific song, artist or album, but occasionally, they’re for a particular subject matter. Someone wrote, "I’m here with two teen boys who are pretending I’m not with then. Do you have anything that screams teenage angst?"

Kantor responds to all requesters, though sometimes not until after the game. If he doesn’t get to your song, he may promise to play it the next time you’re at Fenway.

While walking to work before each game, Kantor said he always wonders what surprises might be in store.

“There’s usually a moment of — not panic, but, like, I don’t know what songs people are gonna throw at me,” he said. “Maybe I get no requests tonight, or maybe I get requests where I’m flummoxed and stumped and failing.”

Josh Gold-Smith, who tracks professional sports organists on his Twitter feed, Organist Alert, marvels at Kantor’s skill.

“He’s able to recall or learn songs from scratch within minutes, while paying attention to the flow of the game. He has a tremendous musical ear with an innate ability to multi-task. But he also has an almost encyclopedic knowledge of music," Gold-Smith said. "Those qualities, plus the social media interaction, have made him one of the most popular organists in baseball."

Kantor admits the Twitter interaction has fundamentally altered his job.

“It’s now 10 times harder and 5 times more fun,” he said. “That’s not an awesome ratio, but 5 times more fun is pretty cool, so I’m OK with it.”

With the game over, Kantor was packing up when Mike, the Weezer fan, and his wife, showed up.

“I just wanna thank you for everything you do, and always taking my Weezer requests,” Mike said. “You always kill it on the organ. It’s amazing.”

It’s just the sort of feedback that keeps Kantor going.