The study of W algebras began in 1985 in the context of two-dimensional conf- mal field theories, the aim being to explore higher-spin extensions of the Virasoro algebra. Given the simultaneous growth in the understanding of two-dimensional metric gravity inspired by analyses of string models, it was inevitable that these algebras would be applied to give analogues of putative higher-spin gravity t- ories. This book is an exposition of the past few years of our work on such an application for the algebra: in particular, the BRST quantization of the n- critical 4D string. We calculate the physical spectrum as a problem in BRST cohomology. The corresponding operator cohomology forms a BV algebra, for which we provide a geometrical model. The algebra has one further generator, of spin three, in addition to the (spin two) energy-momentum tensor which generates the Virasoro algebra. C- trary to the Virasoro algebra, it is an algebra defined by nonlinear relations. In deriving our understanding of the resulting gravity theories we have had to - velop a number of results on the representation theory of W algebras, to replace the standard techniques that were so successful in treating linear algebras.

Directly from the Mission District in San Francisco, the explosive fusion of Latin, salsa and rock is chronicled from a writer who has followed the music and the musicians for over 30 years. The book covers the stories of prominent Latin rock bands including Santana and Malo, examining in detail the pioneering records and the ways in which both reflect a wide spectrum of Latin influences. It highlights the cast of characters and emerging period in the US during the late '60s, with all the cultural background events including the Summer of Love, Woodstock, political activism, and the record label expansion. Legendary figures such as Bill Graham, Clive Davis and the Escovedos family play crucial roles in the development of this sound. As Latin music continues to become more mainstream, the interest in its musical roots grows. This book sheds light on these musical pioneers, and is gorgeously illustrated with over 800 BandW photos by Jim Marshall, Rudy Rodgriguez, Joan Chase and others, plus artwork of dozens of rare album covers.

The Spanish Civil War was a time of repression and political conflict, the art of the theatre suffering with other art mediums and the Spanish people as a whole. This text draws upon rare and previously unpublished material in order to study this subject.