A part-time DJ is in line to seize the helm at Goldman Sachs — and he’s already got the bank’s executives playing musical chairs.

David Solomon — who on top of holding the No. 2 spot at the Wall Street powerhouse does weekend music gigs under the stage name DJ D-Sol — is the driving force behind a surprise shakeup in the bank’s trading division, sources told The Post.

That’s despite the fact that Solomon isn’t expected to succeed Lloyd Blankfein as chief executive until at least later this year, insiders said. Solomon’s picks to run two top divisions have, in turn, left many worried about their jobs, according to sources.

Last week, Goldman announced that Pablo Salame, the 52-year-old vice chairman and global co-head of the $12 billion securities division, will “retire” next month — leaving Ashok Varadhan as its sole head. Isabelle Ealet, global co-head of the securities division, also is leaving, although that was expected, according to three sources.

“That’s David Solomon’s choice,” one source said of Varadhan’s surprise ascent.

Traders had widely expected Salame — a blunt Ecuador native who quickly rose to prominence after joining the bank in 1996 — to stay and take over the role rather than Varadhan, a trading prodigy who nevertheless has reportedly entertained leaving Goldman.

Insiders note that Salame was close to former co-president Harvey Schwartz, who abruptly left Goldman earlier this year after losing out to Solomon in a battle to succeed Blankfein. Had Schwartz prevailed, Salame probably would have, too, sources said.

With Salame’s exit, those who curried favor with him are now worried that they’ll be next to be shown the door. At Goldman, the success of traders and bankers can, along with their performance, be tied to the boss they’re aligned with during times of management change, sources said.

“A lot of the senior people were betting that Pablo would get the role,” another source told The Post. “There are people who bet on the wrong horse.”

It wasn’t immediately clear after last week’s announcement if Salame and Ealet would be replaced, but insiders say there is now an intense scramble to win the promotion.

Employees speculate that among the likeliest candidates are the four next-highest trading division chiefs: Jim Esposito and Justin Gmelich, co-chief operating officers of bond, currency, and commodities sales and trading; and Paul Russo and Michael Daffey, co-chief operating officers of equities sales and trading.

The internal struggles are coming as rumors about Blankfein’s retirement are flying fast and loose on the bank’s trading floor.

In March, the Wall Street Journal reported he could leave as early as December. Blankfein, who has run the bank since 2006, could announce a December retirement soon after coming back from summer vacation, said one person who often speaks with the CEO.

Others dismissed all talk as rumor. “Who the hell really knows?” one exec said. “I think maybe [Blankfein] knows — in the back of his head.”

Jake Siewert, a Goldman spokesman, declined to comment.