Complex sentence: The Strand group performed at two large science fiction conventions in Los Angeles and San Francisco, were offered a spot at The Mabuhay, a local punk club, and performed for children's television of Argentina.
Split into simpler sentences: The Strand group had performed at two large science fiction conventions in Los Angeles and San Francisco. They were offered a spot at The Mabuhay, a local punk club, and even performed for children's television of Argentina.