Maybe a Piaggio? They have a unique sound.
Nope, it was a Starship. The swept canard and wings are much different than the Piaggio's, as asicer's post reveals. I've never seen a Starship in flight around the DFW area or heard one on ATC. It might have been N903SC, which is registered to a Dallas LLC and based at KADS. The aircraft owner has restricted its appearance on FlightAware.
I have a good story about the first Starship I saw. It was in May 1990, and I had just arrived at KIND on a Southwest Airlines flight. I was there to attend the Indianapolis 500, a ritual that had started with my Dad in 1968, when I was eleven years old. As we taxied toward the terminal, the plane passed the Signature FBO, and on the parking ramp near the perimeter fence was a Starship. Wow! I have to check this out. After I retrieved my bag and got a rental car, I drove over to the FBO and parked.
Taking note of the registration number of the Bonanza parked next to the Starship, I went inside and approached the counter. I explained to the attendant that I had arrived earlier in the day in N2774G (or something like that) and had inadvertently left my wallet in the plane.
He smiled, nodded, politely led me to the airside door, and I walked out onto the ramp, carrying my backpack. I went over to the Starship and Bonanza, pulled out my camera, and began taking pictures of the beautiful and unusual aircraft.
It only took a couple of minutes before a rampy noticed me, went inside, and returned, trailed by the agent. He wasn't as friendly this time.
I mumbled a combination excuse and apology, and escaped. Seeing the plane up close was way cool. It was a beautiful example of Burt Rutan's fertile mind, and when I returned to Dallas, my pilot friends were anxious to see my spy shots.