from the introduction

AMONG the hundred and ten operas the stories of which are told in this book are all the grand operas that have been put upon the stage during the last five seasons in the four opera centers of the eastern United States— New York, Chicago, Philadelphia, and Boston—and also half a dozen others whose premiere or first American production or American revival is announced for the coming season by one or another of the leading companies.
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With each opera is given interesting and carefully verified data. The name of the composer and the date of the first production serve to place the opera in the line of artistic succession. The name of the writer of the book, or libretto, is often of great musical or literary significance. The full list of the characters, together with their singing parts, is included in order that the musical nature of the work and the dramatic force of each scene may be realized.
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