"Graham Wade, in his article on Andrés Segovia for the Grove music Online, describes his impact on the progress and status of the guitar as a recital instrument as ‘immeasurable’. Supporting the adjective with the statement: ‘He revitalized traditional playing techniques and expanded the repertory by editing many transcriptions and by his massive work in inspiring composers to write new music for the instrument.’ Indeed, not only did he established the guitar as a classical instrument by performing in the most renowned concert hall, but he also worked actively to develop its repertoire. Segovia’s 36 years collaboration with the Italian/American composer Mario Castelnuovo-Tedesco resulted in 35 works featuring the guitar.

For the first time, both sides of the correspondences between Andrés Segovia and a composer are gathered. They offer a significant insight on the role of Andres Segovia in the development of the guitar repertoire through his collaboration with Castelnuovo-Tedesco. The letters reveal previously unknow biographical information which, in several cases, correct misinformation in the Segovia literature.

The editing and publication of Castelnuovo’s repertoire is, also, discussed in detail within the letters. Editions and publication of the ‘Segovia repertoire’ has been and is still one of the main topics of debate in the classical guitar world. This thesis answers numerous questions on the role of Segovia in the composition, editing, and publishing process of Castelnuovo’s guitar repertoire.

Furthermore, the collection of letters represents an unprecedented source of information for performers. The numerous details about Castelnuovo’s guitar works revealed in the letters contribute to a new understanding of the repertoire, including the inspiration behind numerous composition elements.

It is, therefore, an important read for any researcher on 20th century guitar repertoire as well as for every guitarist who want to perform Mario Castelnuovo-Tedesco’s music. "