Rhett Miller stood onstage March 20, before the Dallas Mavericks were to play Golden State.

The Mavs had lost five of eight. Much of the energy from their early season surge had fizzled. Still, Miller -- the 40-year-old vocalist for the acclaimed alt-country band Old 97's and also a successful solo singer-songwriter -- made a declaration to the pregame concert crowd: "We're going to start a winning streak today."

They did. Five in a row. Now Dallas is on a 12-2 tear that put it in the Western Conference finals.

Chris McKay/Getty Images Rhett Miller's Dallas die-hard fandom for Dallas sports is a family tradition.

"I'm not going to take credit for it ... [but] they've been great ever since," Miller said.

OK, so he's not really serious. Plus, Dallas did lose four straight in the time after Old 97's -- whose album "The Grand Theatre Vol. 2" drops July 5 -- performed for fans at American Airlines Center (followed by Miller singing the national anthem).

The point is, Miller loves his Mavs. And all Dallas sports (even with his musician-like anti-jock look). He lives in New York and spent some time in Los Angeles, but the Metroplex -- and its teams -- occupy his heart.

After all, they're in his blood. Except not in the most brag-about-it way.

His grandfather, Giles Miller, owned the area's first NFL franchise, the Dallas Texans. But not the Texans who later became the Kansas City Chiefs. No, the Millers' Texans folded before the 1952 season ended.

"I was born into a family that would have been wealthy," Miller said, "had it not been for the failure of a Dallas football franchise."

Not that he's bitter. He's had quite the career -- in music, of course, but also in sports.

Read More »