Chromatical playing on diatonic harmonica: From physical modeling to sound synthesis

To understand chromatical playing on a diatonic harmonica one must consider both the instrument and the musician. For each of the harmonica holes, two reeds share a single reed chamber and, theoretically, there is one reed for each direction of airflow (blown or drawn note) while both reeds practically contribute to escaping airflow. The airflow model must take into account all 3D local airflow free jets passing between the plate and the local bent portion of the studied reed to give access to realistic numerical simulations. But to explain bends and overnotes, the vocal tract of the musician must be included and adapted. The vocal tract model must include at least a pressure excitation in the back cavity, the palatal constriction, the front cavity and a mix between lips channel and harmonica chamber. And, the physics involved in the whole model is acoustical nonlinear fluid mechanics rather than acoustical wave propagation. All relevant physical phenomena will be described and illustrated, sound synthesis given to listen. Moreover, a description of the time-variation of the vocal tract model will be proposed for ones thinking about real-time sound synthesis.