(b. Pesaro, June 11, 1555; d. Mar. 23, 1627), one of the most learned musical theorists of the early Italian school. He spent the greater p a r t of his life a t Venice, where he was admitted to the priesthood, received the tonsure as a monk of the Order of S. Augustine, and officiated as maestro di cappella in the great church belonging to the Order. In 1592 he was in tho service of Wilhelm, Duke of Bavaria, as ' musico,' and in 1593 he was invited to Vienna by the Archduke Charles, who made him his Kapellmeister some years later. In 1619 he returned to Venice, and devoted himself to the completion of his great theoretical work, the first portion of which was published before his departure to Vienna. The work on which Zacconi's fame is based is entitled Prattica di musica utile et necessaria si al compositore . . . si anco al cantore, and is dedicated to Guglielmo Conte Palatino del Reno, Duca dell' alta e bassa Baviera, etc. The first pa rt was published a t Venice in 1592, and reprinted in 1596. The second part, also printed a t Venice, first appeared in 1619. The contents of tho work are divided into four books, wherein the treatment of consonant and dissonant progressions, the complications of mode, time and prolation, the laws of cantus fictus, with many like mysteries, are explained with a degree of lucidity for which we seek in vain in the works of other theoretical writers of the polyphonic period-the Dodecachordon of Glareanus and the Musicae activae Micrologus of Ornithoparcus alone excepted. I t may, indeed, be confidently asserted th a t we are indebted to these two works, in conjunction with the Prattica di musica, for the most valuable information we possess on these subjects- information, in the absence of which Josquin's * Missa didadi ' and portions even of Palestr in a 's ' Missa l'homme arme,' to say nothing of the enigmatical canons of the earlier Flemish schools, would be quite undecipherable. Lib. I. of the Prattica di musica is subdivided into 80 chapters, 23 of which are occupied with dissertations on the origin and history of music, interspersed with definitions, and other introductory matter, of no great practical utility. Cap. xxiv. treats of the ' Harmonic Hand ' ; Cap. xxv. of the figures used in notation ; Cap. xxvi. of the stave of five lines ; and Cap. xxvii. of the clefs, of which several forms are given. Caps, xxviii.-xxxiii. trea t of measure, time and various forms of rhythmic division (misura, tatto, e battuta). Caps, xxxiv.-xxxv. describe the time table, beginning with the Maxima, and ending with the Semicroma. Caps, xxxvi.-xxxvii. describe the time-signatures (Segni del Tatto). Caps. xxxviii.-xl. tre a t of solmisation. Caps, xli.- xlii. describe the office of points generally, and especially th a t of the point of augmentation. Caps, xliii.-xlvi. furnish some very valuable information concerning the ligatures in common use towards the close of the 16th century. Cap. xlvii. trea ts of rests ; xlviii.-xlix. of the B molle and B quadro ; l.-li. of the diesis ; and Iii. of syncope. Caps, liii.-lv. are devoted to the consideration of certain difficulties connected with the matters previously discussed. Caps, lvi.-lvii. tre a t of canon, and the different ways of singing it. Caps, lviii.-lxvi. contain the rules to be observed by singers, illustrated by many examples and exercises, and throw great light upon the laws of cantus fictus, the management of complicated rhythmic combinations and other mysteries. Caps, lxvii.- lxxi. tre a t of the duties of the maestro di cappella and singers. Caps, lxxii.-lxxiii. describe the villanella and canzonetta, while Caps, lxxiv.-lxxx. sta te the mutual qualifications of singers and composers. Lib. I I . is divided into 58 chapters, of which the first 5 t re a t of the different species of mood, time and prolation. Caps, vi.-vii. describe the points of division, alteration and perfection. Cap. viii. corrects some prevalent errors in the matter of perfect time. Caps, ix.-xxxvii. trea t of the mutual adaptation of mood, time and prolation, and the different kinds of proportion. In illustration of this subject, Cap. xxxviii. gives, as examples, the Kyrie, Christe, second Kyrie, the beginning of the Gloria, the Osanna and the Agnus Dei, of Palestrina's * Missa l'homme arme,' with full directions as to the mode of their performance. Aided by Zacconi's explanations, Dr. Burney was able to score them. 1 Caps, xxxix.-lviii. bring the second book to an end, with the continuation of the same subject. Lib. I I I . consists of 77 chapters, treating of the different kinds of proportion. Lib. IV. is divided into 56 chapters, of which the first 37 tre a t of the twelve modes. Of these Zacconi, in common with all the great theoretical writers of the polyphonic school, admits the use of 6 Authentic and 6 Plagal forms, and no more ; and, not content with expunging the names of the Locrian and Hypolocrian modes from his list, he expunges even their numbers, describing the Ionian mode as Tuono XI., and the Hypoionian as Tuono X I I . 2 Caps, xxxviii.-xlvi. tre a t of instrumental music, as practised during the la tte r half of the 16th century, and are especially valuable as describing the compass and manner of using the various orchestral instruments as played by 1 See D r . B u r n e y 's * E x t r a c t s , ' B.M. A d d . MSS. 11,581. 2 See Vol. I I I . p . 482. Peri, Monteverdi and their immediate successors, in their early essays in opera and oratorio. Caps, xlvii.-lv. trea t of the tuning of musical instruments ; and the concluding chapter, lvi., furnishes us with a table, exhibiting on a great stave of eleven lines, the compass of the instruments most commonly used a t the time tho book was written. We subjoin the compass of each instrument, on an ordinary stave, and translated into modem notation : Cornetti Bianchl o Negri. Vio linl.1 Pifarl. Dolziane. Corner torto. Cornamuti torti. Fagotto chorista. Trombone. (" C a n to . Flauti. | C a n to .4 Viole.3 T en o re . Doppiani. The foregoing synopsis gives but a slight indication of the value of the Pratticn di musica, which supplies information on every important subject connected with tho music of tho 16th century, information in many cases obtainable from no other source. The work is now extremely scarce and costly; complete copies will, however, be found in the British Museum and the R.C.M. (For continental copies see Q.-L.) w. s. R. B i b l .- F . B a t i e t . t . i , Un m u s ic i *ta pesarese n e l seccolo X V I ( 1 9 0 5 ) ; i d e m , S o t i z ie su la v ita e le opcre d i L. Zac eonl (191*2); H . K r e t z s c h - M a r . L. Z a rco n i's l.eben a u f U ru n d se ine r A utobiographic (1 9 1 0 ) .