The singer's agent, Trey Newman, tells TMZ ... Sundance Head was at his ranch in rural Texas on Friday when he was shot.

We're told paramedics were able to get Sundance Head in stable condition and he's being airlifted by helicopter to a hospital in Tyler, TX.

Sundance Head's agent says the singer was the one who called 911 after the shooting ... and his wife, Misty, says paramedics told her the bullet hit her husband in the stomach.

Unclear how Sundance Head was shot, but his agent says he goes hunting on his ranch. Sundance Head posted a photo on social media Friday morning from inside a big tent with a cot, saying he was waking up to the "sound of silence" ... so he may have been on a hunting trip.

The agent says the wife relayed that the bullet missed all of Sundance Head's organs ... with the bullet lodged in a fatty area of the stomach.

We're told the shooting is being considered an accident at this point.

Meanwhile, Sundance Head's wife is asking for prayers ... and she says she's on her way to visit him at the hospital.