This article is about the opera singer. For the performance artist, see Theo Adams. For the DC Comics character, see Black Adam. Theo Adam, 1987 Theo Adam (born 1 August 1926) is a distinguished German classical bass-baritone who had an active international career in operas, concerts, and recitals from the 1940s through the 1990s. He particularly excelled in portraying roles from the operas of Richard Wagner. On the concert stage, he was a much admired Bach singer and also drew acclaim for his interpretation of the title character of Felix Mendelssohn's Elijah.