Tempo Estimation

図: Tempo plot: derived from rhythm recognition results

Tempo $T$, the sequence of instantaneous tempo estimated by $\tau_t={x_t}/{\hat{q}_t}$ from observed IOIs $X$ and the estimated rhythm $\hat{Q}$, often contain errors as shown in Fig. 3 such as double tempo, half tempo, and errors due to confusion by triplets mainly caused by the nature of rhythm vector. We model the distribution of estimated tempo $T$ by a Gaussian mixture distribution and apply the EM (Expectation-Maximization) algorithm to estimate the true tempo. After estimating the tempo, note values are estimated again.