The new thing on Facebook is brands singing to their Facebook fans. Last month, Kraft Macaroni & Cheese personally thanked 4,632 fans who had "liked" a status update with a six-minute-plus a cappella song. Now, A&T and BBDO New York (with director Joe Sabia) have upped the ante with a real-time series of personalized songs that the AT&T House Band is making up and singing on the spot and posting to Facebook and YouTube. Yesterday and today, the band—otherwise known as the virtuoso collective CDZA, made up of Julliard-trained musicians led by Sabia and Michael Thurber—have been holed up in a Brooklyn studio tracking a Facebook app that lets AT&T fans tell the brand why he or she is "awesome." The band has been improvising songs for as many people as it can—a total of 305, as of this writing. (If you want to get in on the action, you'll have to hurry—the 48-hour marathon ends today.) The band was also nice enough to perform a song for me personally (a '70s soul jam, see below), which I'll have to add to my personalized Old Spice response video as one of the weirder experiences I've had in social media.