_Second Principal Epoch._--From the commencement of the Opera until the development of Instrumental Music and Chamber Music (A.D. 1600-1700). Division of the Art of Music into Church Music and Operatic Music. First appearance of some distinguished performers on instruments. 1, Italy (with Spain and Portugal); 2, France (with the Netherlands); 3, England; 4, Germany (with Bohemia, Hungary, Poland, Sweden, and Denmark). _Third Principal Epoch._--From the development of Instrumental Music until the end of the Eighteenth Century (A.D. 1700-1800). Division of Church Music, Operatic Music, and Instrumental Music. 1, Italy (with Spain and Portugal); 2, France (with the Netherlands); 3, England; 4, Germany (with Bohemia, Hungary, Poland, Sweden, and Denmark). After these Divisions and Sub-divisions follows an alphabetically-arranged Register of the names of the musicians who are mentioned in the different Periods and Epochs. But also here we have Divisions and Sub-divisions, so that the Register, in fact, consists of six Indices, each containing the musicians of a certain epoch or a certain country, from A to Z. The author says that the plan of the work renders this arrangement necessary; but, as he does not prove his assertion, students using the work for reference will probably arrive at the conviction that one general Index, containing all the names in alphabetical order, would be more convenient. Another disadvantage is that the Indices are entirely restricted to the names of musicians, no reference being made to important events relating to the history of music. In fact, the chief aim of the work is to notice a great many musicians. The number of composers, theorists, and performers entered amounts to 1713, of whom 236 belong to the ancient Greeks and Romans, 132 to the Middle Ages, and 1345 to European nations from A.D. 1400 to 1800. Many of these musicians have left no mark upon the history of their art, and their names have justly fallen into oblivion. These might better have been omitted. Of what use, for instance, can it be to the student to be supplied with the names of the musicians who played before Alexander the Great on the occasion of his marriage with Roxanen, at Samarkand, in the year B.C. 328? Especially among the 1345 composers who distinguished themselves during the four centuries from A.D. 1400 to 1800 are many who might now as well have been left at rest. What possible advantage can the student derive from a record of mediocre pianoforte composers whose productions were not held in much esteem even during their lifetime? On the other hand, it was prudent in the author not to extend his list beyond the year 1800. The distinguished musicians of the present century are known to readers who take an interest in the history of the art, and who are most likely to use the book. Anyhow, it would be a delicate task to admit the names of living musicians, some of whom may still become more celebrated than they are, while others may