When KK Downing quit Judas Priest a decade ago, he at least appeared to be a bit fed up with, and frustrated by, the whole business of playing in a heavy metal band. As co-founder and lead guitarist of the Brummie legends and with 40 years of active service on his resumé, his place in the genre’s official pantheon of giants was already secured. And so KK slipped into the shadows, much to the annoyance of diehard metalheads everywhere.