When and how was the art of music conceived?

Scholars have a number of views on the conception of the art of music, of which the following is the most prominent one. 

The origin of music was from Brahma the creator of Vedas. Brahma imparted this art to Shivji and through Shivji it passed on to devi Saraswati. Saraswati is known as 'वीणा पुस्तक धारिणी' thereby bestowing her the position of the dean of music and literature. Narad attained the knowledge of this divine music from Saraswati . Narad in turn imparted this knowledge to the heavenly beings like the gandharvas, kinnars and the apsaras. 

Divine beings like Bharat muni, Narad muni and Hanuman attained expertise over the music and they descended on earth to spread the knowledge of music far and wide. 

Samaveda, one of the four branches of vedas, discusses music in depth. Indian classical music has been deeply inspired by spirituality, due to which its beginnings have been believed to take the role of being an instrument in achieving, the final goal of human life- ‘ Attaining Moksha’  

The importance of music is also made clear by the great Indian teachers by giving it the stature  of being the Fifth Veda or the पंचम /गंधर्व वेद . 

Bharat muni’s Natya shashtra was initially a treatise,  in which the root principles of drama, Dance and music were rendered. 

Indian classical music is considered to be the most complex and complete system of music in the whole world