Last 7 days, studies suggested that Blackstone (NYSE: BX) was preparing to commit $1 billion in new music legal rights as portion of an settlement with Hipgnosis founder Merck Mercuriadis. Now, the billion-greenback partnership has formally launched.   New York City-primarily based Blackstone – which in April obtained Demise Row Information owner eOne Songs (now MNRK Songs Team) for $385 million – formally unveiled its settlement with Hipgnosis (specially Hipgnosis Music Administration – not the investment decision fund itself) and Merck Mercuriadis this early morning. The entities’ partnership “will at first produce c.$1 billion to obtain tunes rights and deal with catalogues,” according to higher-ups, with an emphasis on buying…