DELIA WALLIS has had an impressive international career spanning more than 30 years, singing in opera, concert and recital. She made her debut as Tebaldo in Don Carlos with the Royal Opera House, Covent Garden at age 22, and subsequently appeared with many of the leading opera houses of North America and Europe.\r Ms. Wallis was born in Chelmsford, England and completed six years of training at the Guildhall School of Music and Drama and the London Opera Centre.