Peter Csathy What do Stevie Nicks, Chrissie Hynde, Neil Young and Bob Dylan have in common? Apart from being iconic rockers, they are the latest in a seemingly endless stream of superstars who are doing what for many — themselves included — was previously unthinkable: selling their songs and recordings.Who are the buyers? Activist IP aggregators like Primary Wave, which acts as a partner and typically buys a share of rights rather than the full bundle.