“Don’t buy The Black Album, I’m sorry.” Ah yes, another posthumous album from the late and lamented Prince--or, as we prefer to think of his erstwhile persona, TASTAHA-TAFKAP (The Artist Soon to Acknowledge Himself as the Artist Formerly Known as Prince). Since he and Warner Bros. aren’t seeing eye to eye on what his output should be right now, he’s apparently resolved for the time being to only give the label material recorded during his previous life. First out of the vault was “Come,” and now--hot on its heels and in stores on Tuesday--comes the legendary “Black Album.” Question: Is there any halfway-hardcore Prince fan in America who doesn’t already own a copy? “Black” may have sold more units as a bootleg in the seven years since it was recorded than “Come” has on the open market in recent months.