The Left Bank Organization confirms Debbie's appearance and submitted an advertisement (from the Evening Standard, Friday 5 May 2000, page 57) for this event. Transcript:

A musical celebration in the presence of
Dame Elizabeth Taylor

Royal Albert Hall
Friday 26 May

Featuring
Charles Aznavour, John Barry, Tony Bennett, Andrea Bocelli, Jamiroquai,
Lesley Garrett, Deborah Harry, Ute Lemper, Martine McCutcheon, Reba
McEntire, Marti Pellow

plus other surprise guests to be announced.

Tickets: £20, £30, £50
Available from:
Royal Albert Hall Box Office 020 7589 8212
Evening Standard Readers Hotline 0870 333 1123 www.hotticketsdirect.co.uk

Ticket agents:
Ticketmaster 020 7344 4444
Way Ahead 020 7403 3331
First Call 020 7420 1000
Stargreen 020 7734 8932

All tickets are subject to a booking fee unless purchased in person from
Royal Albert Hall

For exclusive £100 box seat call 020 7838 3109

For the benefit of the Red Hot AIDS Charitable Trust & the Elizabeth Taylor
AIDS Foundation.

Note: this is expected to be a brief appearance.