AUDIENCE members raised their phones in the air at Grey’s sixth Annual Legends Of Music Seminar, to capture Deborah Harry perform live in the Debussy. A cappella, with delegates providing a beat to sing to by, Harry (still effortlessly cool) sang the opening lyrics to Heart Of Glass.

The impromptu performance came after a conversation with Tim Mellors, Grey’s worldwide chief creative and fan of the Blondie frontwoman, discussing her transition from “shy observer” to lead singer of the punk rock and new wave band – and her part in the cultural revolution of their time.

“We were very lucky to get in on a birth of change,” said Harry. “There was an extremely young focus in New York at that time. It wasn’t a popular city and there was no money – but what happened in the mid-80s changed fashion, music and a lot of opinions.”

Mellor quizzed Harry about her experience as a burgeoning star in CBGB’s in Manhattan:“No one starts from the top – that would be awful if you started at your best and then declined!” said Harry. “I’m pleased I was part of Hilly’s [founder of CBGB’s] concept to create a place for original music – it was really like we were at rock ‘n’ roll school.”

Mellor said that Harry’s own transformation to one of the most enduring and creative icons was, in part, because she was such a fascinating character with a light/dark duality.

“I always felt I had determination,” said Harry. “Where it came from, I don’t know. But what happened to me was born out of a desperation really – a desperation to express myself.”

The Blondie singer is the latest in an A-list roster that in recent years has included Donovan, John Legend, Tony Bennett, Yoko Ono in 2010 and, last year, Patti Smith.

After the Grey seminar Debbie Harry gave an impromptu press conference...