ATLANTA — On a recent weekday afternoon, the fast-talking entrepreneur and advertising executive Gary Vaynerchuk, better known as Gary Vee, jumped out of an Escalade and marched into a recording studio an hour later than he was supposed to, trailed by a videographer as if he was the talent.

Inside, the up-and-coming local rapper Lil Keed, a protégé of Young Thug with a movie-star smile and winning demeanor, was patiently standing by, having decided to record a song while he waited for a sit-down with a man twice his age, who had nothing to offer at the moment but advice and conversation.

Why one of the hottest young artists in the city had found himself at the scheduling whims of a former New Jersey wine salesman-turned-social-media guru might be hard to fathom from the outside. And yet it spoke clearly to Vaynerchuk’s rising stock in the universe of hip-hop, where he has become an influential cheerleader, mentor and middleman, placing early bets on rising acts — as he did as an investor in Facebook, Uber and Venmo — and helping introduce them to his Fortune 500 client roster.

“Bro, you need to get very serious about TikTok,” Vaynerchuk, 44, told Keed, 21, after a few minutes of small-talk, as silence fell over the crowded control room. “You can get five times bigger,” he promised, explaining if one line goes viral, “your career is completely in a different place — you get one of those, you’re selling out Madison Square Garden.”