It seems almost unthinkable but, on March 29, after all the debates and discussions, there will be a final parting of the ways. An old, highly-profitable alliance will be dissolved as an institution that once ruled the waves goes it alone.

Yes, never mind Brexit, the final Friday in March will also see Band-exit, as Martin Bandier – the cigar-chomping, twinkly-eyed chairman and CEO of Sony/ATV, the world’s No.1 music publisher – will depart the company for pastures new. And, ...