This number was on my caller ID when I got home, but they didn't leave a message.  I have family in Dallas, and I thought someone might have been trying to get a hold of me for them.  When I called the number back to make sure, the phone rang 3 or 4 times, then I heard a click with music or TV noise in the background, a second click and silence, another click with the same background noise, then yet another click and the silence was back.  I stayed on the line for several seconds and hung up.  I then waited a minute or two and called back, and I got a busy signal.  I have no idea who or what this is.