Von Putlitz had been appointed Theatre Intendant at Munich long before through the personal efforts of Richard and Cosima Wagner, cf Ernest Newman,[2] and offered a chance to sing solo.

In 1906, aged 29, Erb started an unpaid probationary year at Stuttgart (beginning January 1907, which led to a five-year paid contract.

He had the help of a young répétiteur, a singing teacher, a drama tutor (Hans Islaub, who got rid of his Swabian accent) and a ballet master.

Through the singer Elsa Wiborg, he was given the chance to sing privately for the King and Queen; then, on 14 June 1907, he made his debut in Evangelimann at the new Hoftheater.

He then appeared as Wagner's Lohengrin (in which the shimmering brightness of his voice was especially effective), as Buddha in Adolf Vogel's Maja, as Little Massarena in Le domino noir, Achilles i Gluck's Iphigenia in Aulis, Walter and as Gounod's Faust.

Erb, deeply undermined, sacked him and nearly broke with von Putlitz, but instead they agreed that he pass the winter season 1908 as leading lyric tenor for the brand-new Theatre at Lübeck.

Greatly inspired, he added Lionel (Martha), Manrico (Il trovatore), Gomez (Das Nachtlager in Granada (Kreutzer)), Froh (Das Rheingold), Florestan (Fidelio), Alessandro Stradella in Friedrich von Flotow's opera, the Duke of Mantua (Rigoletto), Turiddu (Cavalleria rusticana), Fenton (Die lustigen Weiber von Windsor (Carl Otto Nicolai)), Hoffmann in Jacques Offenbach's opera, and Alfred in Die Fledermaus to his repertoire.

Hans Pfitzner as Director of the Strasbourg Opera from 1910, sought to stage his Der Arme Heinrich at Stuttgart, but needed a suitable tenor to convey the spiritual depths of the work.

The first and third performances were with the élite soloists Maria Jeritza, Margarethe Siems, Herman Jadlowker: the second was the Stuttgart team, Erb as Bacchus.

The theatre valued his growing dramatic power and insight, and he relished such works as Franz Schreker's Der ferne Klang and (later) Die Gezeichneten.

In Brussels, after a concert, an officer gave him his gold finger-ring as the token of homage to his art, from him, an unknown soldier returning to the front who should perhaps be dead tomorrow.

In that period he was learning the Pfitzner, Wolf and Schreker roles, and (by his own account) increasingly sought to develop the emotional, spiritual and intellectual depth of his interpretations.

The poet Romain Rolland heard the 10 March 1916 performance at Basel Minster under Herman Suter (with Maria Philippi) and extolled it, and soon Amsterdam also recognised a new genius.

Thomas Mann, who had seen Erb's St Matthew Passion, described how he completely grasped the spiritual meaning of Palestrina, and Pfitzner felt he had found his ideal interpreter.

(Ivogün had come to Munich in Walter's troupe in 1913, and in 1916 she and Erb realised they were in love, during a performance of Erich Wolfgang Korngold's Der Ring des Polykrates.)

Erb always wanted to sing Wolfgang Amadeus Mozart roles, but it was during rehearsals for a Schreker work that he suddenly had to stand in as Belmonte in Die Entfuhrung.

They appeared together as Ernesto and Norina, Almaviva and Rosina, Chateauneuf and Marie, Hoffegut and Nachtigall, Martha and Lionel, Fenton and Frau Fluth, Max and Aennchen, Wilhelm Meister and Mignon, Ritter Hugo and Undine, Fenton and Alice, Duke and Gilda, Palestrina and Ighino, Bacchus and Zerbinetta, Rudolf and Mimi, Hoffmann and Olympia, and above all in the Mozart roles, Belmonte and Konstanze, Tamino and the Queen of the Night, Ferrando and Despina and Ottavio and Zerlina.

During the voyage home in March 1925, news came to the ship that Friedrich Ebert had died – and for the first time Adolf Hitler spoke again openly in Munich.

But Bruno Walter had left Munich for the Berlin-Charlottenburg Städtische Oper in 1922: his successor Hans Knappertsbusch had little time for the Swabian tenor, whose contract expired in summer 1925.

Erb continued to sing the Matthew Passion Evangelist yearly at Amsterdam for Willem Mengelberg, and in the course of thirty years sang it some 360 times, in most major German town and cities, and in Zürich, Bern, Basel, Lucerne, Solothurn, Lausanne, Milan and Brussels, under Bruno Walter, William Mengelberg, Hermann Suter, Fritz Busch, Hermann Abendroth, Alfred Sittard, Wilhelm Furtwängler, Karl Straube and Eugen Papst.

He sang it throughout the second war, and after, in Germany: a 1940 reviewer described his Cologne cathedral performance as an 'unfassbaren, übermenschlichen, unirdisch wirklichen Vollendung' (an inconceivable, more-than-human, supernally real perfection).

Between 1935 and 1940 he made an impressive series of records (HMV) of Schubert, Schumann, Brahms and Wolf songs, accompanied by Sebastian Peschko, Bruno Seidler-Winkler or Gerald Moore.

The many strands of his singing experience, the thoughtfulness of his Pfitzner, Wolf and Schreker, the musical discipline of his Bach and his Mozart, Beethoven, Gluck, Weber and lyric Wagner roles, had laid the foundations for this last work, in which he excelled.

In his Doktor Faustus, Thomas Mann refers to the first performance of Adrian Leverkühn's work Apocalypse as being under Otto Klemperer in 1926 at Frankfurt.

The narrator role 'is here written for a tenor..., one of castrato-like high register, whose chilly crow, objective, reporter-like, stands in terrifying contrast to the content of his catastrophic announcements....