Electric Flag had the shortest career of any significant jazz-rock group: just eighteen months. They intended to combine blues, rock, soul, jazz, and country; as the first group to use two horn players in a rock context, they ended up sparking the rock-with-brass trend. Formed in 1967, the band established itself at the 1967 Monterey Pop Festival and followed with a first album that made the Top Forty. But ego conflicts among the members soon undermined them. Although it lasted less than two years, Electric Flag was very influential because of the musicians' technical virtuosity.