A signal processing apparatus and method is disclosed by which signal components of different musical intervals of an audio signal can be obtained with a small amount of arithmetic operation. A re-sampling section re-samples an audio signal inputted thereto with a sampling frequency equal to a power-of two times a frequency at a boundary of an octave. An octave dividing block divides the audio signals outputted from the re-sampling section into audio signals of octaves and outputs the resulting audio signals to respective band-pass filter banks. Each of the band-pass filter banks includes 12 band-pass filters and extracts and outputs audio signals of 12 musical intervals from the audio signals of one octave. The invention can be applied to a signal processing apparatus which analyzes, for example, signal components of musical intervals of an audio signal.