Abstract: This invention is singing evaluation system and evaluation method for all type Karaoke. Offline, online, wireless Karaoke has Karaoke track and visual display feature. The singing evaluation system extracts user's singing melody in realtime. Extracted melody is expressed in notes of 4-tuple: pitch, onset, duration and sound intensity. User's melody information is visualized and displayed in comparison to original melody of the song. User's singing melody and original melody of the song is compared by each note and when the difference is above pre-set level, grading system's octave is automatically adjusted. User can choose karaoke track type freely enabled by offsent sequence. Another distinctive characteristic of this invention is practice-by-phrase and evaluate-by-phrase function. The function allows users to break down a song to the length of 2 to 3 phrase and practice the specific phrases till perfect.