I have just posted a revised and expanded introductory essay which replaces the one I wrote ten years ago for this site. The current version is an adaptation of the paper I delivered at Princeton in April and reflects more recent research. Although I do not have a formal research assistant for this ongoing project, my friend Lucas Freire has helped me immeasurably by uncovering a number of metrical psalters of which I was previously unaware. For both of us metrical psalmody is something more than an avocation. Obrigado, Lucas! Deus te abençoe.