Mary, Did You Know? is a Christmas song with lyrics written by Mark Lowry and music written by Buddy Greene. It was originally recorded by Christian recording artist Michael English on his self-titled debut solo album in 1991 (English and Lowry were both members of the Bill Gaither Vocal Band at the time).
Found this great little snippet on Buddy Greene's FAQ page. Pretty much applies to acting — just about any business.
Q: How do I get started in the music business?
A: I can only speak to those who desire to make a living as a musician. Practice a lot, perform as often as possible, receive formal training if possible, and accept the opportunities that are given you and make the most of them. If you've got real talent, a good work ethic, and you're willing to "show up for the audition," whatever that is, most likely you'll get some work. Then you'll either love it enough to keep trying or not. I think you have to have a strong desire in the first place to want to perform or compose or produce or publish- you know you just can't get enough of the world of music. Then it's a matter of humbling yourself, working hard at your instrument, learning the business, making contacts, gaining experience little by little, knocking on doors, and marketing yourself. In other words it's going to take a lot of self-initiative and patience. Most important, remember that the talent to make music is a gift. So whether you end up making a living with it, singing in the choir, or just having an occasional jam session, you can be thankful for the gift and provide much satisfaction for yourself and whoever's listening.
Q: Does your family get to travel with you?
A: Not if they can help it, unless there's a payoff for them, like an Alaskan cruise or a trip to Disney World. It's really not much fun for them to follow me around while I ply my trade.
Q: Is it hard on them with you traveling all the time?
A: Sometimes, they don't even know I'm gone. Here's a story from a few years ago... I said goodbye to the family early one morning, and told my girls I'd see them in a few days. I then flew to Miami for a concert. That night in my hotel room, my cell phone rang. It was Erin, my oldest, teenage daughter. "Hi Erin," I said. "Hi Dad- could you come pick me up?" (She was at school, after a ball game and needed a ride home). I paused for a second and said, "well, that's gonna be kinda hard, Erin, since I'm in MIAMI!" "Oh", she said. "Well, then, do you know where Mom is?"