1. A system for multifaceted singing analysis comprising: a musical audio signal generating processor operable to generate one or more modified musical audio signals, of which music and vocal characteristics are modified, from each of musical audio signals of music including singing voice; a frame signal acquiring processor operable to acquire a plurality of frame signals in time series from each of the musical audio signals by applying a predetermined window function to one of the musical audio signal of music including singing voice and the one or more modified musical audio signals; a vocal feature vector estimating processor operable to estimate a plurality of vocal feature vectors for each of the frame signals acquired from each of the musical audio signals; an analysis-fitted segment estimating processor operable to estimate analysis-fitted segments by determining whether or not each segment in the frame signals is fitted for analysis, based on the vocal feature vectors as estimated by the vocal feature vector estimating processor; a vector discretizing processor operable to discretize the plurality of vocal feature vectors in the analysis-fitted segments to convert them into a vocal symbolic time series composed of a plurality of vocal symbols; a topic analyzing processor operable to analyze, using a topic model, a plurality of the vocal symbolic time series obtained for the respective musical audio signals of music including singing voice and the modified musical audio signals, to generate a vocal topic distribution for each of all the musical audio signals, the vocal topic distribution being composed of a plurality of vocal topics each indicating a relationship of one of the musical audio signals with the other musical audio signals, and to generate a vocal symbol distribution for each of all the vocal topics, the vocal symbol distribution indicating respective occurrence probabilities for the vocal symbols; a vocal topic distribution storing processor operable to store a plurality of the vocal topic distributions generated by the topic analyzing processor; a vocal symbol distribution storing processor operable to store a plurality of the vocal symbol distributions generated by the topic analyzing processor; and a multifaceted singing analyzing processor operable to perform multifaceted analysis of singing voices respectively included in the musical audio signals of music including singing voice and the modified musical audio signals, based on the vocal topic distributions stored in the vocal topic distribution storing processor and the vocal symbol distributions stored in vocal symbol distribution storing processor.