After a break, I have returned to John Tilbury’s mammoth biography of Cornelius Cardew. It is 1966; Cardew is swanning about in Buffalo, New York while back in London his wife Stella struggles with four children and virtually no money in their top-floor flat off Warwick Road. She writes a stream of letters to Cardew complaining bitterly about the couple who have come to stay at the flat. They add to both her childcare responsibilities, leaving her to act as nursemaid to their pneumonia-wracked child while they go off gallivanting to swish parties, and to her financial problems, in that they never contribute a penny towards the housekeeping – this in spite (or more likely because) of what Stella describes as their exaggerated and unseemly preoccupation with money. She is desperate to get rid of them, but all her efforts fail until eventually Cardew writes a letter ordering them to leave.

And the names of these charming guests? The man is Tony Cox, and the woman is his then wife, a Japanese artist called Yoko Ono.