Complex sentence: Tichatschek (11 July 1807--18 January 1886), originally Tichaček, was a Bohemian tenor opera singer highly regarded by Richard Wagner, who created the title roles in his operas "Rienzi" and "Tannhäuser".
Split into simpler sentences: Tichatschek (11 July 1807--18 January 1886), originally Tichaček, was a Bohemian tenor opera singer highly regarded by Richard Wagner. He created the title roles in Wagner's operas "Rienzi" and "Tannhäuser".