12. A method for multifaceted singing analysis implemented in a computer to cause the computer to execute the steps of: generating 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; acquiring a plurality of frame signals in time series from the musical audio signals by applying a predetermined window function to one of the musical audio signals of music including singing voice and the one or more modified musical audio signals; estimating a plurality of vocal feature vectors for each of the frame signals acquired from the musical audio signals; estimating analysis-fitted segments by determining whether or not each segment in the frame signals is fitted for analysis, based on the vocal feature vectors estimated in the step of estimating a plurality of vocal feature vectors; discretizing 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; analyzing topics using a topic model by analyzing a plurality of the vocal symbolic time series obtained for the respective musical audio signals of music including singing voice and the one or more modified musical signals, to thereby generate a vocal topic distribution for each of all the musical audio signals whereby the vocal topic distribution is 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 thereby generate a vocal symbol distribution for each of all the vocal topics whereby the vocal symbol distribution indicates respective occurrence probabilities for the vocal symbols; storing the vocal topic distributions generated by the step of analyzing topics in a vocal topic distribution storing processor; storing the vocal symbol distributions generated by the step of analyzing topics in a vocal symbol distribution storing processor; and performing multifaceted analysis of singing voices respectively included in the musical audio signals of music including singing voice and the one or more 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.
12. A method for multifaceted singing analysis implemented in a computer to cause the computer to execute the steps of: generating 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; acquiring a plurality of frame signals in time series from the musical audio signals by applying a predetermined window function to one of the musical audio signals of music including singing voice and the one or more modified musical audio signals; estimating a plurality of vocal feature vectors for each of the frame signals acquired from the musical audio signals; estimating analysis-fitted segments by determining whether or not each segment in the frame signals is fitted for analysis, based on the vocal feature vectors estimated in the step of estimating a plurality of vocal feature vectors; discretizing 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; analyzing topics using a topic model by analyzing a plurality of the vocal symbolic time series obtained for the respective musical audio signals of music including singing voice and the one or more modified musical signals, to thereby generate a vocal topic distribution for each of all the musical audio signals whereby the vocal topic distribution is 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 thereby generate a vocal symbol distribution for each of all the vocal topics whereby the vocal symbol distribution indicates respective occurrence probabilities for the vocal symbols; storing the vocal topic distributions generated by the step of analyzing topics in a vocal topic distribution storing processor; storing the vocal symbol distributions generated by the step of analyzing topics in a vocal symbol distribution storing processor; and performing multifaceted analysis of singing voices respectively included in the musical audio signals of music including singing voice and the one or more 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. 15. The method for multifaceted singing analysis according to claim 12 , wherein: the musical audio signals are accompanied by metadata; and at least a part of the metadata is displayed together with analysis results when displaying the analysis results on a display portion, in the step of performing multifaceted analysis of singing voices.