1. A method of identifying, among a plurality of music audio files in digital format generated by machine, a first one of the music audio files, the method employing a segment of audio data which is derived from the first music audio file and comprising the steps of: (a) inputting the segment of audio data generated by the machine into three different extraction processes, the three different extraction processes including (1) an IMFCC 1 (first improved mel frequency cepstrum coefficients) extraction process, the IMFCC 1 extraction process performing a conventional MFCC (mel frequency cepstrum coefficients) algorithm but not performing a logarithmic step of the conventional MFCC algorithm, wherein IMFCC 1 audio features are output, (2) an IMFCC 2 (second improved mel frequency cepstrum coefficients) extraction process, the IMFCC 2 extraction process performing the conventional MFCC algorithm but not performing both the logarithmic step and a discrete cosine transform step of the conventional MFCC algorithm and instead performing an ICA (independent component analysis) process, wherein IMFCC 2 audio features are output, and (3) an ICA 1 (improved independent component analysis) extraction process performing a conventional ICA (independent component analysis) process but subjecting the segment of audio data to pre-emphasis preprocessing and windowing preprocessing, wherein ICA 1 features are output; (b) creating an observation vector containing the IMFCC 1 audio features, the IMFCC 2 audio features and the ICA 1 audio features; and (c) recognizing the machine generated first music audio file using the observation vector and a database trained using only observation vectors containing IMFCC 1 , IMFCC 2 and ICA 1 audio features for each respective target music audio file; wherein the audio features comprise features obtained by analyzing the audio data, or a transformed version of the audio data, to derive a transform based on its audio features, and applying the transform to the audio data, or the transformed version of the audio data respectively, to obtain amplitudes of the audio features.