In June 1967, at the urging of his friend and business associate Lou Adler, Davis attended the Monterey Pop Festival. He immediately signed Janis Joplin with Big Brother and the Holding Company, and Columbia went on to sign Laura Nyro, The Electric Flag, Santana, The Chambers Brothers, Bruce Springsteen, Chicago, Billy Joel, Blood, Sweat & Tears, Loggins & Messina, Aerosmith and Pink Floyd (for rights to release their material outside of Europe). The company, which had previously avoided rock music (its few rock acts prior to the Davis presidency included Dion DiMucci, The Byrds, Simon & Garfunkel, and Paul Revere and the Raiders), doubled its market share in three years.