We built and trained a model of intonation in continuous Mandarin speech based on the Stem-ML model of interacting accents. With this model, we found that we can accurately reproduce the intonation of the speaker using only one accent template for each lexical tone category. The resulting parameters are interpretable, and we find that the fitted model is consistent with linguistic expectations. Stem-ML is a phenomenological model of the muscle dynamics and planning process that controls the tension of the vocal folds. It describes the interactions between nearby tones or accents.