Kurt Moll, who has died aged 78, was an imposing presence in any opera house; his height appeared greater than the 6ft 2in he claimed, his voice sounded deeper than the booming basso profundo he was billed as, and his personality exuded warmth and charm both on stage and off.
The "big man from Cologne" appeared at Bayreuth for a decade from 1968; at the Royal Opera in London he was seen in Weber's Der Freischutz in 1977 and in Wagner's Parsifal in 1979 and 1980 when, according to one critic, he supplied "a steady, warmly and musically sung, finely detailed Gurnemanz".
He was renowned for his interpretation of Baron Ochs in Strauss's Der Rosenkavalier, which he once described as "probably the hardest role in the bass repertory", singing the part with Kiri Te Kanawa at the Metropolitan Opera, New York, and recording it on seven occasions.
Meanwhile, his Commendatore in Mozart's Don Giovanni, returning from the grave to condemn the seducer Giovanni to hell, would send shivers down the spine of even the most hardened listener as he resonantly hit the lowest notes of the register.
Kurt Moll was born at Buir, west of Cologne, on April 11, 1938.
His early ambition was to be an industrialist or a cellist, but the conductor of his school choir encouraged him towards singing. "I have not touched the [cello] in 40 years, but I know how it goes, and what I learnt then still helps me a lot now," he said in 2003.
He studied at the Hochschule fur Musik in Cologne and had several minor roles at Cologne Opera in the late 1950s before joining Aachen Opera, making his debut as Lodovico in Verdi's Otello.
Soon he was singing bigger parts, such as Sarastro in The Magic Flute, yet he paced his career carefully, declining more taxing Wagnerian roles such as Wotan and Hans Sachs.
"If I had agreed, I would not be singing any more," he said in 2003.
There was more regional experience, including Ramfis in Aida at Mainz and the title role in Boris Godunov at Wuppertal, before he settled at Hamburg Opera, performing some 70 roles over five years.
In December 1970, he sang in Beethoven's Missa Solemnis at St Peter's, Rome, with Placido Domingo and Christa Ludwig conducted by Wolfgang Sawallisch to mark the bicentenary of the composer's birth.
Pope Paul VI was present and the televised occasion was directed by Franco Zeffirelli.
His US debut was at San Francisco in 1974 and four years later he sang Hermann in Wagner's Tannhauser at the Met conducted by James Levine.
"I rush around like a maniac, and of course it plays havoc with my marriage," he complained of his busy schedule in 1979. "One's personal life just goes to pieces... it's the price you pay if you want an international career."
Always good natured, Moll was philosophical about the intrusion of surtitles into the opera house. "It is good that they translate the words," he said, although he found that the audience "laugh when they read the joke not when we say it. But it doesn't disturb me."
His final appearance was as the nightwatchman in Wagner's Die Meistersinger conducted by Zubin Mehta in Munich in July 2006, with the rest of the cast joining the audience at the curtain call to give him a remarkable ovation.
His advice to younger singers was to work hard. "Make music and make theatre," he once said, "because first and foremost you're an entertainer."
Moll married Ursula Pade in 1968; they had a son and two daughters.