Shadaj is considered as the fundamental pillar of Raag-Sangeet. It is the reference note that gives birth to various other musical notes. Among these musical notes, a very special note that is double the frequency of Shadaj is also called Shadaj (Tar). The reason for this nomenclature is the audible similarity of these two notes. Despite this similarity, they hold subjective musical relationships with any other note. The present study is an analytical approach to highlight the similarity and differences in the musical nature of Shadaj and Tar Shadaj. The analysis concludes that the two Shadajs appear analogous to identical twins that are genetically the same, but subjectively responsive to the same environment.
Sati, Himanshu and GK Bhide. "Shadaj and Taar Shadaj: Similar yet Unique." Sangeet Galaxy, no. 1, January 2020, pp. 6-12.