Blending jazz, 20th century classical and soundtrack idioms, the Modern Jazz Quartet treated concerts like chamber performances. The first lineup of the MJQ formed in 1951; by 1955 the iconic lineup of pianist and leader John Lewis, vibes man Milt Jackson, bassist Percy Heath and drummer Connie Kay was set. For the next 19 years, until their celebrated 1974 farewell performance, the MJQ were based on the dynamic tension between Lewis's complex arrangements and the freewheeling intensity of Jackson's solo showcases.