Pointless factoid: Until, I think, the late 18th or early 19th Century, the sharps and flats (say C# and Db) were actually slightly different pitches. There were keyboard instruments with two sets of skinny black keys, dual-manual pianos, one for the sharps, one for the flats, etc. I suspect that the piano makers got pissed off and banged a few heads together to resolve it all. And I can see why keyboardists (being a little bit of one meself) would prefer playing in, say Db. You can play a pentatonic major or minor scale starting from any black key, using only the black keys. And it's right handy if you're in a "horn band", seeing as how all the horns are pitched to "black key" keys. Oh and that bit there is why "Johnny B Goode" is actually in Eb. Chuck's piano player, Johnnie Johnson had decades of big band/jump band experience and Chuck was no stranger to horn bands either.