Complex sentence: Funtastic! was sung and performed by Sha-Na-Na's Jon Bauman and The Funtastic Singers who sang the chorus and it was also the official theme to "The Funtastic World of Hanna-Barbera" block.
Split into simpler sentences: Funtastic! was sung and performed by Sha-Na-Na's Jon Bauman and The Funtastic Singers who sang the chorus. It was also the official theme to "The Funtastic World of Hanna-Barbera" block.