In 2003, Slash, Duff McKagen and Matt Sorum of Guns N’ Roses; Dave Kushner of Danzig; and Scott Weiland of Stone Temple Pilots formed the hard rock, supergroup Velvet Revolver. With such talent, fan expectations were very high. The band’s debut album, “Contraband,” did well enough commercially, selling four million copies. Yet, hardcore Guns N’ Roses, Danzig and Stone Temple Pilots fans were left feeling high and dry. Something was amiss, they said, some indescribable quality common to all great bands: Velvet Revolver had no chemistry.