The modern revolution of the 1920s was similar to the British Invasion of the 1960s which brought music from outside and established it as the new mainstream. Music developed quickly during this period, with the recording becoming a total package and multi-tracking allowing for layered instrumentation. Rock music changed the relationship between composer and performer and amplification became more prominent, making horns less important. Identifiable instrumental riffs were used to catch the listener's attention before the singer entered.