Also notable was the festival's innovative sound system, designed and built by audio engineer Abe Jacob, who started his career doing live sound for San Francisco bands and went on to become a leading sound designer for the American theater. Jacob's groundbreaking Monterey sound system was the progenitor of all the large-scale PAs that followed. It was a key factor in the festival's success and it was greatly appreciated by the artists—in the Monterey film, David Crosby can clearly be seen saying "Great sound system!" to bandmate Chris Hillman at the start of the Byrds' soundcheck. Lighting by Chip Monck attracted the attention of the Woodstock Festival promoters.