1. A computer readable storage device for storing computer readable instructions, the computer readable instructions providing a beat analysis module when executed by one or more processing devices, the computer readable instructions comprising: logic configured to preprocess an audio item; logic configured to form a matrix based on samples of the audio item; logic configured to determine a Fast Fourier Transform (FFT) of rows of the matrix; logic configured to construct a vector y which contains an average frequency spectrum energy of each of the rows of the matrix; and logic configured to perform an Expectation-Maximization (EM) iterative procedure on the basis of the vector y to determine an average beat period P of the audio item, the EM iterative procedure being performed over plural representations of the audio item.