Disclosed are a method and a system of separating and extracting unified major sound sources from a mixed musical signal. A unified sound source separation system includes a first sound source separation unit to separate a first sound source having unique time-domain and frequency-domain characteristics from a mixed musical signal which includes a plurality of sound sources using time-domain and frequency-domain characteristics, and a second sound source separation unit to separate a second sound source existing in a predetermined stereo sound image position from the mixed musical signal using stereo channel information.