In the late 19th century guitar composers were both writing and playing their own music in the Romantic style, such as Coste did in Paris. The transition in style and performance practice was realized by Tárrega and his contemporaries. Then, guitarists played either their own compositions or transcriptions of non-guitar music, mainly composed in the National Style.This had its home in Spain with Albéniz, Granados. The next generation of guitarists, such as the modern players Pujol, Llobet and Segovia, mainly performed music by other composers, while at the same time making the transition from Nationalism to Internationalism. Above all, it was Segovia who had a large pool of modern composers - from Moreno Torroba to Ponce - who brought performing and composing for the instrument up to an international standard, establishing Modernism as the norm. Along with these developments in the international rise of the guitar, its performance practice changed from participation in mixed concerts with original compositions, through mixed program recitals with original works and transcriptions, towards eclectic program recitals with varied programs of original works by non-guitarist composers, transcriptions and interpretations in various styles. These changes in the musical style, mentioning the genres composers used, are analyzed by way of an Identification System of Analytical Items with well defined criteria of style elements and formal characteristics, to give evidence to the description of the music. The analysis of the sources, the research in literature and the interpretation of the subject, result in a contribution to the comprehension of the aesthetics of the different musical styles. This is described in musicological terms by pointing out the most significant characteristics of the styles to the background of sociol-cultural traditions in musical life and the identity of the performer as creative...