He then appeared as Lohengrin (in which the shimmering brightness of his voice was especially effective), as Buddha (in Maja of Adolf Vogel), as Little Massarena (Le domino noir, Auber), Achilles (Iphigeneia in Aulis, Gluck), Walter (Meistersinger) and as Faust (Gounod). By the end of the trial year he had sung at the Hoftheater at 30 evenings or masterclasses: an unparalleled success. Soon afterwards, von Putlitz urging, Erb took singing lessons from Felix Decken, a tenorbuffo, who tried to break and rebuild his technique. 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.
After the first season there (ended April 1909) he returned to Stuttgart and showed how he had benefited from the experience. He returned to Lubeck for a second season in Autumn 1909, and now added Tannhäuser, Les Huguenots, Die Zauberflöte, Die Entführung aus dem Serail, the Götterdämmerung Siegfried, Naraboth in Salome (first produced Dresden 1905), and The Barber of Seville, and Fredy Wehrburg in The Dollar Princess to his performed repertoire. He made his May 1910 farewell in Martha. He also sang then in Kiel and Hamburg, and returned to Stuttgart for the winter season of 1910.
Through Frau Boy-Ed Erb was introduced to Graf von Bernstorff's house at Lake Starnberg, where he also met Felix Mottl, Stenka Fassbender and Graf Sporck (poet-author for Cyrill Kistler's music-drama Kunihild). He sang Schubert for Mottl, who was deeply impressed, and started planning to get him to Munich. Graf Spork, a friend of the Wahnfried house, was also interested, and Erb and Frau Boy-Ed attended a Bayreuth Parsifal with him. But amid the rivalry, a place at Munich was already secure (through Mottl) when, at a concert under Siegfried Wagner's baton, Erb realized he could not work for the latter.
However Pfitzner, seeking to raise a Munich Hoftheater boycott on performance of his works, rewrote the Arme Heinrich role for Erb, and staged it with him at the Prinzregententheater at Munich, privately, whereupon von Speidel for the Hoftheater asked Erb his price and was told 24,000 Marks per year. Munich offered a guest role in Lohengrin, which he took, and later a Florestan and a Hoffmann. In 1912 and 1913 he sang six performances a month at Stuttgart and fitted in guest appearances at Tübingen, Ulm, Lübeck, Berlin, and Wiesbaden. In September 1912 the new Stuttgart Hoftheater was completed, Erb sang Walter in Meistersinger, and was heard by visitors from all over Swabia.
A month later, 25 October, at Stuttgart, Richard Strauss conducted the première of his Ariadne auf Naxos, the original Max Reinhardt production following Le Bourgeois Gentilhomme of Molière. 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. In May 1913 at the Imperial performance at Wiesbaden he sang Hüon in Oberon. The Kaiser said to him, 'You must be a good Lohengrin. Tell Baron von Putlitz I thank him for having sent such a good performer of Huon.' Erb's farewell to Stuttgart after his six years there was as Lohengrin.
He was already singing Strauss's Bacchus and Naraboth, and Pfitzner's Arme Heinrich. Bruno Walter brought Hugo Wolf's Der Corregidor to Munich Festival for him, at some expense, and Erb became completely, almost exclusively associated with it. 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.
During the War the work of the theatre was reduced, and restricted to German and Italian music. In summer 1916, he travelled with the Stuttgart Theatre ensemble to France and Belgium to sing and play to the German troops. He encountered Ravensburger soldiers at Lille. 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. Erb wore it until the outbreak of the second war.
St Matthew Passion
In 1914 Bruno Walter persuaded Erb that he should sing the Evangelist in Bach's St Matthew Passion. His first performance was at the Munich Odeon, March 28th 1915, with Paul Bender as Jesus. 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. He sank his whole artistic personality into the Evangelist, reading what Albert Schweitzer and Heuser had written.
In 1915 Paul Ehlers thought him the finest Evangelist since Heinrich Vögl. A 1916 Cologne performance won extravagant praise, and wonder at his versatility, from Hermann Abendroth, and from the press. 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.
Munich's greatest wartime artistic project was the premiere of Hans Pfitzner's Palestrina in 1917. Erb created the title role, with Maria Ivogün as Ighine. Fritz Feinhals and Felix Brodersen also sang and Walter conducted. The Swiss took the whole show with the Munich ensemble, in midst of war, to Basel, Berne and Zürich. 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. Erb was a very great Mozartian singer, and thereafter he played many roles, including Octavio, Belfiore, Tamino and Ferrando, as well as Belmonte. In 1918, shortly before the end of the war, the King of Bavaria bestowed on Erb (the last) title Königlich Bayerische Kammersänger. During the Rhine occupation early in 1919 Erb was touring the Rhine towns and in Holland with St Matthew Passion. He was held up, returning, at Ingolstadt, and the Munich revolution had settled by the time of his return there.
Between 1920 and 1924 Ivogün toured twice in the United States on her own, and developed a large following there. The couple toured there widely together between December 1924 and late February 1925, when, after Willem Mengelberg had failed to persuade Erb to sing the St Matthew Passion in New York, amid press sensations offering to 'buy' the performance, Erb left Maria to complete her tour and went home. He had two Matthew Passions to deliver each in Munich, Elberfeld, Dortmund, Hagen, Cologne and Haarlem all between 22 March and 13 April. America did not suit Erb as it suited Ivogün, and although their partnership continued for several years, they began to go their separate ways.
Ivogün would not remain under Knappertsbusch, and went to the Berlin-Charlottenburg Oper. In 1926 Erb, Ivogün and their accompanist Michael Raucheisen were giving recitals in Bremen, and shortly before a Duetten-abend Erb tripped on the hotel steps and broke his right leg. Two painful months later in Berlin he resumed singing with Lieder-abends and a Matthew Passion. In 1927 he appeared in London, Covent Garden, as Belmonte, with Paul Bender as Osmin, and after this he sang in Berlin, in The Hague, in Halle, Düsseldorf and Mannheim, as Belmonte, Tamino, Loge, Bacchus, Ernesto and Florestan and in Der Corregidor. In summer 1929 he sang the Matthew Passion at La Scala, Milan, to a very enthusiastic audience.
That July while swimming in the Starnbergersee Erb was dashed against a rock by the sea and found later on the beach by Frau Ivogün. By luck his life was saved, but the convalescence was long and painful and he never fully recovered. In January 1930 he reappeared before the public with Ivogün, and still in much pain travelled to Holland to sing Florestan. In June 1930 he made his last operatic appearance, a performance worthy of his powers, at the Berlin-Charlottenburg Oper under Furtwängler, as Florestan. In April 1931 Erb and Ivogün were divorced, torn apart by deep and conflicting feelings. Two years later he learnt that she had married Michael Raucheisen, his former accompanist, with whom he had hoped to work again: it was a doubly crushing blow.
When Erb left the stage his career was just entering its last great development, which was as one of the most serious and accomplished lieder singers of his age. Between 1935 and 1940 he made an impressive series of records (HMV) of Schubert, Schumann, Brahms and Wolf songs, accompanied by Bruno Seidler-Winkler and 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. His vocal technique, breath control and distinctive tone survived almost unchanged into his mid-seventies. Hans Hotter, who held Erb in high esteem, said that 'it was Paul Bender and Karl Erb who sparked my great love for the art song.'
In 1947, aged 70, he gave a concert for his mother's 90th birthday in his home church at Ravensburg. He died in Ravensburg in 1958.