Music and the ' Teatro de Cordel: In search of a paradigm

Particularly in the eighteenth century, as an alternative to opera as such, there are a number of indigenous traditions of musical theatre: the zarzuela in Spain, the opéra comique in France, the ballad opera in England, the Singspiel in Germany. In Portugal, by contrast, we find a series of phenomena, all with greater or lesser musical content: the operas by António José da Silva ('The Jew') and his imitators; comedies of extremely diverse kinds; entremeus and forças, etc. - the various genres of the so-called 'teatro de cordel'. The rather heterogeneous panorama in Portugal contrasts with the apparent homogeneity of the other traditions mentioned. To what extent can these other traditions shed light on our understanding of the music in the teatro de cordel?