For someone known on campus as “the Toad’s DJ,” Thomas “DJ Action” Jackson is fairly unassuming. When asked what exactly it is he does, he says, “I just show the hell up.” But he does a whole lot more than that.

Walking into the Black Bear Saloon on the corner of Temple and Crown, a pub with thick wooden tables and an old-fashioned style, I found him setting up his equipment as easily as if he were tying his shoelaces. As he hooked up his state-of-the-art turntables to his laptop, fiddling with wires, knobs, and switches in preparation for his weekly gig, he gave me a crash course in deejaying.

DJ Action Maxim #1: “If a DJ doesn’t read his crowd, he’s not a good DJ.”

Apparently, deejaying is all about communicating. “Take those guys over there,” he says, pointing to a table with three men, most likely in their forties, drinking beers and watching a football game. “They were probably born in ’68, so when they were our age, it was ’88. They probably like ‘Bust a Move,’ or INXS.”

When 9:30 rolled around, the house music was turned down as DJ Action started to gear up. Watching him smoothly switch tracks from “Baby Don’t Go” to “This Time” to “Ride Wit U,” I could see how he started to target the incoming crowd of younger, more outgoing bar hoppers. This wasn’t music for your average 40-year-old; it was livelier, more modern, more hip. He anticipated what the crowd wanted to hear, setting up the next track before the first one even finished, spinning the turntable a little to transition seamlessly from one song to the other. And just when you least expected it, he would bust out some Santana to change up the playlist. “You never play too much of one thing — you always play the right thing to keep them there longer,” he says.

The crowd at Black Bear is one matter; the crowd at Toad’s is another one entirely. “You guys like some weird music,” says Action, recounting the time several Yalies asked him to play “Dragostea Din Tei” by O-Zone, a song he had never heard of before.

So, basicallly you judge your audience and make a calculated guess. I can do that. “But when do I get to play what I want?” I asked. Basically, never.

DJ Action Maxim #2: “Take you and your ego home.”

What does DJ Action listen to on his own? Surprisingly, nothing he plays in any of his clubs. “A lot of it is not club friendly; it’s just not popular,” he says. This goes for everything from socially conscious rap to classic rock to jazz.

But DJ Action’s taste in music isn’t the only thing that’s diverse. His personal interests range from hip-hop producers Pete Rock and 9th Wonder to physical therapy and politics. And, while an expert on all things pop from 50 Cent to Rihanna, he also knows the original German title of the fourth movement of Beethoven’s 9th Symphony, “Ode an die Freude” (did I mention he was a German major?). He also makes some music on his own, mixing Wham! with Timbaland to create his own mash-ups. Unfortunately, the Saturday night Toad’s crowd won’t get to hear these. “They’re really more for me,” says Action.

Clearly, it’ll take some practice before I get the hang of this whole deejaying thing, but I’ve got some hope. Action, who is entirely self-taught, started out as anything but a DJ: a pre-med and sometime skier, his attention was focused on becoming a doctor. (If things had gone differently, it would have been Dr. Action.) His father was a music fanatic, but he didn’t want his son to touch turntables. That didn’t stop Action. His sophomore year at Colby College, his roommate, a well-known DJ on campus, suggested he try it out as a way to make some extra cash. As it turns out, he was a natural.

A few years later, as a graduate student at Quinnipiac University with only $200 left in his bank account and his rent to pay, Action started deejaying seriously. As he put it, “I thought to myself, you got this equipment, man. Get busy.”

But, money aside, at the end of the day, it’s all about the music for Action, who has a day job as a physical therapist. “Some people like skydiving. I like deejaying.”

By the time I left the Black Bear, it had started snowing. On any other evening, the saloon would have looked quiet. But inside, DJ Action was halfway into his set, the music pulsing outwards, warm, inviting, into the chilly New Haven night.