Complex sentence: The group performed on countless international tours under the name Obernkirchen Children's Choir, with performances on TV shows such as "The Ed Sullivan Show" (November 29,1964, and December 11,1966).
Split into simpler sentences: The group performed on many international tours under the name Obernkirchen Children's Choir. They made two appearances on "The Ed Sullivan Show" (November 29,1964, and December 11,1966).