There is quite a lot of information to cover so it will be in several parts. The information provided is not meant to be a complete musical analysis or to assist in developing technique, nor to say this music must be interpreted one way and not another. Instead, it is to provide a historic context for the music and musical culture that Villa-Lobos drew his inspiration from and which may inspire you in your own interpretations of the work, at least indirectly, as well as perhaps inspire you to delve deeper into the world of Brazilian music in general.
This analysis will cover just the first two preludes. The Hommage to Bach is covered in detail elsewhere, and the Hommage to the Brazilian Indian and Social Life is straightforward and in my opinion don't necessitate a treatment that first two preludes do. But if anyone would like my opinion on them, feel to ask or comment. My interest and study in diaspora music and culture spans about a decade or more, and was a focus of my studies at university along with guitar, both of which I continue to explore.
Prelude no 1, Homenagem ao Sertanejo Brasileiro - Homage to the Brazilian Desert Man.
The Sertão is a large semi-arid desert of the Northeast of Brazil with a very distinctive milieu from the rest of Brazil with its intersection of Indigenous, Portuguese, Dutch, Moorish, and Sub-Saharan African cultures. Most of the music traditionally from that area is based on the Mixolydian (major scale with b7) and Lydian Dominant (major scale with #4 and b7) modes which may be an influence of the Moors. They were the first Africans to be enslaved and brought to Brazil, but they also ruled the Iberian peninsula prior to their overthrow in the 15th century.
Villa-Lobos uses as his inspiration one such style of music from the Sertão that accompanies a popular sung poetic form called Literatura de Cordel (cord literature), so called because the poetry and associated woodcut artwork are published on cheaply made stamped pamphlets bound with cord. The poetry is accompanied on a 5 double coursed steel string guitar called a viola (the Spanish guitar in Brazil is called violão - meaning big viola). The accompaniment on the viola is generally a single melodic line in unison with the singer over one of the aforementioned modes with open string drones in the basses. Follow the YouTube link below for an example.
Villa-Lobos traveled through the interior of Brazil between 1905 and 1912 when he was still young, and that exposure provided him with a wealth of musical ideas that provided him a wider range of expression than he would have found remaining in Rio or studying strictly classical technique and composition for the rest of his career.
For this piece, Villa-Lobos was inspired by the music of the Sertão but didn't draw as heavily from the tradition as he could have, instead filtering his musical ideas through European art music. Perhaps harking back to the cello, his primary instrument, he inverts the voices and places the melody in the bass and drone accompaniment in the trebles. He uses a 3/4 rhythm instead of the traditional baião common to music of the Northeast (called tresillo in Spanish), makes use of the minor rather than dominant modes, and adds elements of Romanticism and Impressionism.
The B section is interesting, both as a lively contrast to A, but also because it doesn't appear to have any particular connection to other Brazilian musical genres, but does give a faint impression of Aaron Copeland, strangely enough. Though your ears may vary.
Coming soon: A look at the culture surrounding the choro and the Capadócia.