The most important function of musical criticism is, in my opinion, discovering and calling attention to good things the merits of which are not sufficiently known to the public, and to arouse enthusiasm for them. Therefore, instead of writing a compendium of useless knowledge about insignificant composers and antiquated songs, that have merely a historic interest -- making a dry catalog of a thousand pages that nobody would read -- I have endeavored to give this short volume an eminently practical character; ignoring what is antiquated, trashy, or commonplace; mentioning, so far as possible, whatever is good; but dwelling in detail and with enthusiasm only on the best; making the book, in short, a sort of Song-Baedeker, with bibliographic footnotes for the benefit of students who wish to pursue the subject further. - Preface.