This was from Will2017 on Nottstalgia and explains here:

“Three of the Tykons, who went to Cavendish and were in a school group called the Cavochords, asked me to join them. We went to a music night at the school and asked a singer (who also went to Cavendish) to join”. 

The Tykons (formerly The Fantoms) featured Terry Bennett and Rob Duffy who both went on to successful careers in music.

I presume that The Cavochords was a brief name of The Fantoms and relating to the Cavendish school name.