A method for music analysis. The method includes the steps of acquiring a music soundtrack, re-sampling an audio stream of the music soundtrack so that the re-sampled audio stream is composed of blocks, applying FFT to each block, deriving a vector from each transformed block, wherein the vector components are energy summations of the block within different sub-bands, applying auto-correlation to each sequence composed of the vector components of all the blocks in the same sub-band using different tempo values, wherein, for each sequence, a largest correlation result is identified as a confidence value and the tempo value generating the largest correlation result is identified as an estimated tempo, and comparing the confidence values of all the sequences to identify the estimated tempo having the largest confidence value as a final estimated tempo.