The KFRC Fantasy Fair and Magic Mountain Music Festival was an event held June 10 and 11, 1967, at the 4,000-seat Sidney B. Cushing Memorial Amphitheatre high on the south face of Mount Tamalpais in Marin County, California. Although 20,000 tickets were reported to have been sold for the event, as many as 40,000 people may have actually attended the two-day concert, which was the first of a series of San Francisco–area cultural events known as the Summer of Love. The Fantasy Fair was influenced by the popular Renaissance Pleasure Faire and became a prototype for large scale multi-act outdoor rock music events now known as rock festivals.

KFRC was a radio station in San Francisco, California, United States, which made its first broadcast on Wednesday, September 24, 1924, from studios in the Hotel Whitcomb, at 1231 Market Street. KFRC originally broadcast with 50 watts on the 270 meter wavelength, then moved to 660 kHz in April 1927. As part of nationwide frequency reallocations on November 11, 1928, KFRC was moved to 610 kHz, where the call letters remained until 2005.