This article examines the Thai music iconology – with a focus on the instruments and ensembles and their symbolic representations – of monastery murals along the Mae Klong riverside. It also investigates how Thai music iconology links to broader views on Thai music, including those from Buddhism, culture, and social realms. Thirty-eight murals from the Ayutthaya period to the King Rama V period were selected for analysis. Improvised tools from inter-semiotic, multidimensional approach and concepts of iconography were employed in the data analysis. Additionally, an in-depth interview was conducted with key informants, including local intellectuals and experts in the related areas, for data triangulation. The findings show significant influence of music on Thai social forms, religious beliefs, as well as cultural and historical values.