The Black Keys hit Letterman, Pusha T goes Samson, Meat Loaf gets another injury, A-Trak plans electro-psychobilly, and heaps more. Here’s a look at the musical silliness on Twitter today. Half of Duck Soup, producer A-Trak, is learning about psychobilly music. This could work… Dave Stewart, of the Eurythmics and SuperHeavy, is giving away four