The Swiss cellist Thomas Demenga discusses the fierce competition in today’s music world, how students should spend less time online and more practising, and how he can’t always tell the difference between old and modern instruments Occasionally when I do a phone interview, I feel a pang of envy imagining where my interviewee is. I certainly did when I spoke to cellist Thomas Demenga recently for Cozio.com. He’d just arrived in Venice for the start of a sabbatical, after 35 y