Complex sentence: The role of Adolar in Weber's opera "Euryanthe", premiered in 1823, was created for him, and he was a soloist in the premiere on 7 May 1824 of Beethoven's 9th Symphony at the Theater am Kärntnertor.
Split into simpler sentences: The role of Adolar in Weber's opera "Euryanthe" (premiere 1823) was created for him. He was a soloist in the premiere on 7 May 1824 of Beethoven's 9th Symphony at the Theater am Kärntnertor.