Charismatic, driven and passionate -- this is how people described music producer John Hammond, the man behind famous acts such as Bruce Springsteen, Billie Holiday and Bessie Smith. Those same qualities can be attributed to Bryan Greenberg ("Prime," TV's "How to Make It in America," "One Tree Hill"), who steps into Hammond's shoes for the HBO film "Bessie."

Aside from acting, Greenberg's busy developing several projects, including his third solo album, and he's the voice for The Olevolos Project, created to fund scholarships for needy children in Tanzania.

amNewYork spoke with Greenberg about becoming John Hammond and his upcoming charity brunch on Saturday at Gallow Green at the McKittrick Hotel.

As an actor, are you worried about your next role?

Yeah I worry. It sucks. It's the blessing and the curse of our jobs. I don't worry that it keeps me up at night, but what I've been doing more of is developing. I'm taking the power into my own hands by producing. I want to direct something, and I'm developing a TV show right now, so I'm trying to be a little more proactive than waiting for a script to fall in my lap.

You're a musician as well, do you see that as separate from your acting?

On "One Tree Hill" I got to do both, but it's hard. With film and television shows they go so fast, whereas music you need to plan months in advance, and I can't really do that. I just had to say, "OK music is going to be my passion, and my career will be as an actor." I just finished my third album called "Everything Changes" and I'm going to put it out this month on May 26. I'm psyched about it. It's cleansing. It's a way to free up and be in the music, and you have a little more control too.

What was your research like for John Hammond?

I went online. There's some video clips of him, and he was very charismatic, a very captivating kind of guy, who could take over a room, and he was a great salesman. I was constantly listening to his cadence and clicked into that. People in the music business gave me props. They were like, "You nailed him." It felt cool because I've never played a real guy before. I was just kind of swinging with it.

What made you get involved with the project for Tanzania?

My cousin started this charity called The Olevolos Project, which sponsors children in Tanzania. We have about twenty kids go to school. We give them clothes, food, shelter, and an education. It's a long-term investment and we want to keep these kids from grade school all the way up through vocation school or college. We hand delivered laptops for them. This is the fourth year we're doing this charity event and it's a really fun party. The kids' education wouldn't be possible without this fundraiser.

What's your ultimate goal?

Getting them to learn how to type on a computer is a win. If they get a job working for a hotel, that's a win. We're talking about 60% unemployment over there. It's a small scale, but that's how it starts. They're small goals, but that's how you start changing the world.

On TV: "Bessie" premieres on Saturday at 8 p.m. on HBO.

If you go: The 2015 Olevolos Project Brunch Party Fundraiser is at Gallow Green at the McKittrick Hotel on Saturday from 1-4 p.m., 524 W. 27th St., olevolos2015.eventbrite.com, $150-$2,000.