The voices of the group were all done by Bagdasarian. He recorded his voice and then sped up the playback to create high-pitched voices. It was so unusual and well-done that it earned the record two Grammy Awards for musical engineering. Bagdasarian, performing as the Chipmunks, released a long series of albums and singles. Bagdasarian died in 1972. The characters were revived in the 1980s and 1990s, with the voices being performed by Ross Bagdasarian, Jr. and his wife Janice Karman.