Biblioteca de la Guitarra y Cuerda Pulsada

In Portugal, as in many parts of Southern Europe and Latin America, the guitar was for centuries the preferred instrument for the accompaniment of singing and dancing. It was only during the nineteenth century that the viola— as the five-course guitar was known in that country — was replaced in urban areas by the so-called Portuguese guitar, an adaptation of the cittern-derived English guitar, or guittar. Even so, the violaremained an important instrument in rural areas of Portugal, the Azores and Madeira, as well as in Brazil, Portugal’s largest former colony. The viola, henceforth guitar, was less expensive than most string or wind instruments of similar quality, but it also owed its popularity
among amateurs to an alternative type of music training that developed alongside the instrument’s evolution, a kind of musical subculture that did not rely on traditional staff notation, but rather on tablature and cyphering.
Until the late eighteenth century, tablature was the standard form of notation for the guitar, lute, and numerous other plucked string instruments, even for types of music we may call ‘learned’, or ‘scholarly’, such as ricercares, fantasias, variations and more stylized and elaborated dance suites. Tablature can be a complex system, and in many cases more precise than staff notation. Although the type of tablature most commonly found in eighteenth-century Portuguese sources is fashioned on Italian models, with horizontal lines for the strings and numbers for the frets, it lacks rhythmic indications, bringing us to the paradoxical situation that what made music accessible then makes it elusive now.
The presence or absence of rhythm, or duration signs, in a specific source is an important factor in determining the level of formal musical training of its creators and users. Likewise, it poses some interesting questions concerning the level of autonomy enjoyed by the performers in matters such as variation, embellishment and improvisation...)

Harmonic Patterns and Melodic Paraphrases in Eighteenth-Century Portuguese Music for the Five-Course Guitar