Julie Greenwald Chairman/COO, Atlantic Records Group

At Atlantic, Greenwald has reaped the benefits of a diverse roster that includes rock stalwarts, pop upstarts and singer-songwriters. 

"You want to be strong in every area," she says. "This year we had No. 1 albums from Ed Sheeran, Coldplay, Trey Songz and Slipknot -- and Charli XCX, Ty Dolla Sign, Vance Joy and Clean Bandit all had big records." Atlantic's 7.1 market share as of the end of the third quarter is second only to Republic.

Strength in every area is part of her management style as well, since during her formative years at Def Jam, the Catskills-raised, Tulane-educated Manhattan resident worked in nearly every department in the company, starting as Lyor Cohen's assistant in 1992. "I got my hands dirty running every side of the company," she says. "I understand how hard it is to get records played at radio and to make a good video and come up with creative copy for an ad."

WPMG-Place Hot 100 Radio 

Greenwald's momentum looks set to carry into 2015. "I'm about to drop a new K. Michelle album and a new David Guetta album, and I have a bunch of newbies lined up, like Hoodie Allen and Melanie Martinez and Sevyn Streeter." The married mother of two prides herself on making a company of 270 employees a nimble one. "We are a very big organization," she says, "but we are set up so that each individual artist gets the bespoke service, time, love and attention."

My First Job: "I was a teacher in the New Orleans public school system in the Calio projects through Teach for America. It taught me a lot about patience, understanding and being resourceful."

How I Mentor: "I spend a lot of time with women inside my company. It's important to me that they understand that I understand how hard it is to juggle it all."