Santiago de Murcia remain  may have been related to the stringed instrument makers, Gabriel and Antonio de Murcia, but this has never been proven. Although he mentions the guitarist and composer Francisco Guerau in the introduction to his own printed collection of guitar music, there is no evidence that he actually studied with Guerau.

In his printed collection of guitar music "Resumen de acompanar" Murcia describes himself as Master of Guitar to the Spanish Queen Maria Luisa Gabriela de Savoy. She was the first wife of the first Bourbon king of Spain, Felipe V, a grandson of Louis XIV of France who succeeded to the Spanish throne on the death of Carlos II in November 1700. The marriage took place by proxy in Turin on 11th September 1701. On 3rd November marriage was re-celebrated in Figueras in Catalunya. In April 1702, Felipe V left on a tour of his Italian possessions appointing Maria Luisa as regent in his absence. There is no reason to suppose that Murcia travelled with him to Naples, Italy, or met the composers Arcangelo Corelli and Alessandro Scarlatti. Maria Luisa arrived in Madrid on 30th June and Murcia is not likely to have been appointed as her Master of Guitar before this date. It is assumed that he held the post until her death in 1714. Antonio de Murcia was appointed instrument maker to the Queen in 1704.

From 1714 Santiago de Murcia lived in the house of Jacome Francisco Andriani, Extraordinary Envoy for the Catholic Cantones (those areas of Switzerland that remained Catholic at the Reformation) and Caballero of the Order of Santiago.

Although two of the surviving manuscript collections of Murcia's music - "Passacalles y obras" and "Codice Saldivar no. 4" - came to light in Mexico in modern times, they were most probably taken there at a later date by subsequent owners. It now seems unlikely that Santiago de Murcia actually travelled to Mexico himself. "Passacalles y obras" is dedicated to a certain Joseph Alvarez de Saavedra, but it is not known whether this is the same "Joseph Alvarez" who died in Puebla in 1737.

Apparently Andriani had trading links with the Latin America, especially with Chile and Mexico. The most likely scenario is that Murcia made manuscript copies of his music for patrons which were exported to the New World.