his in many books of German lieder, but whatever their genius may have been, they have not handed down such monuments of greatness as exist in the works of Isaac. In the higher forms of church composition they scarcely competed with him at all.
According to one tradition he was born at Prague, and Ambros devotes a charming page of his history to showing the Bohemian character of some of the subjects used by the composer in his masses. He appears to have spent much of his time in Florence, and here he was sometimes called by the grand title 'Arrhigo Tedesco' in strange contrast to the modest, quaint 'h. yzac,' another variation of his name. His position in Florence, and one date in his life, is shown by a MS. said by Dr. Rimbault to have been in the library of Christ Church, Oxford, but of which we can find no trace there at present. In 'The Musical World' (Aug. 29, 1844) Dr. Rimbault describes this MS. as containing the music composed in 1488 by Henry Isaac for the religious drama, 'San Giovanni e San Paolo,' written by Lorenzo de' Medici for performance in his own family. He also states that Isaac was the teacher of Lorenzo's children, which fact we presume he learnt from the same MS. M. Fétis shows (1) that he was still, or again in Florence many years after 1488, for Aaron speaks of being intimate with Josquin, Obrecht and Isaac in that city, and Aaron could not have been twenty years old (i.e. old enough for such friendship) until the year 1509; (2) that he was also at one time in the service of the Emperor Maximilian I, who reigned from 1486–1519; and (3) that he must have died some years before 1531, according to a note made upon a MS. of that date in the Munich Library, containing a work begun by him and finished by his pupil Senfl.
Of Isaac's works, first in importance come 23 masses, 10 printed, and 13 in MS. (1) The Library of the Lyceum at Bologna has a copy of the 'Misse Heinrici Izac,' printed by Petrucci in 1506, containing 5 masses, 'Charge de deul,' 'Misericordias Domini,' 'Quant jay au cour,' 'La Spagna,' 'Comme femme.' (2) Rhaw's 'Opus decem missarum 4 vocum' (Wittenberg, 1541) contains the 2 masses 'Carminum' and 'Une Musque de Biscay.' (3) 'Liber quindecim missarum,' etc. (Nuremberg, Petreius, 1539) contains the mass, 'præclara,' one of the most remarkable of the composer's works. It is composed on a subject of 4 notes reiterated without cessation throughout the mass. Some of the numbers, such as the 'Et in terra pax' and the 'Qui tollis,' have the character of slow movements by the lengthening of the four notes over several bars, the simple accompaniments of the other parts being very beautiful. The subject is kept in the treble nearly throughout the mass, which is one of Isaac's peculiarities. It is presented in various forms in the earlier movements, first announced in triple time, then in long notes with accompaniments in triple time, till in the Credo it bursts out Alla Breve, forming a majestic climax. The Mass exists in score in the Berlin Library amongst the MS. materials collected by Sonnleithner for a history of music. A copy is also in the Fétis Library at Brussels (No. 1807). (4) Ott's collection, 'Missæ 13, vocum' (Nuremberg, 1539), contains two masses, 'Salve nos,' and 'Frohlich Wesen.' One movement, 'Pleni sunt,' from the latter, is scored in Sonnleithner's MS.
The 13 MS. masses are mentioned by Ambros in his History of Music (iii. 386)—in the Royal Library at Vienna, eight—'Missa Solennis,' Magne Deus, Paschalis, De Confessoribus, Dominicalis, De B. Virgine, and two De Martyribus, all in 4 parts; and in the Munich Library, four 6-part ones,—Virgo prudentissima, Solennis, De Apostolis, and one without name, and a 4-part one, 'De Apostolis.' A MS. volume of Masses in the Burgundy Library at Brussels (No. 6428) contains the 'Virgo prudentissima' under the title 'Missa de Assumptione B. V. M., hēric ysac.'
Eitner's Bibliographic der Musik-Sammelwerke (Berlin, 1877) mentions upwards of forty collections between the years 1501 and 1564, which contain motets and psalms by Isaac. The Dodecachordon of Glarean contains five, three of which Burney (ii. 521–4), Hawkins (ch. 70) and Forkel, have printed in their Histories, Burney having copied them all in his note-books at the British Museum. Wyrsung's 'Liber selectarum cantionum,' etc. (Augsburg, 1520), contains five of the most important of Isaac's works of this class, amongst them two 6-part motets, 'Optime pastor' and 'Virgo prudentissima,' dedicated respectively to the Pope Leo X and the Emperor Maximilian I. An excellent MS. copy of this work exists in the Fétis Library at Brussels (No. 1679). Of Isaac's lieder, Ott's collection of '115 guter newer Liedlein' (Nuremberg, 1544) contains 10. One of them, 'Es het ein bawer ein töchterlein,' is given in score by Forkel in his History. This collection has lately been reprinted by the Gesellschaft für Musikforschung (Liepmanssohn, Berlin). Förster's collection, 'Ein auszug guter Teutscher liedlein' (Nuremberg, Petreius, 1539) contains four, and amongst them 'Isbruck [Innsbruck] ich muss dich lassen,' the words said to have been written by the Emperor Maximilian. The melody was afterwards sung to the hymns, 'O Welt ich muss dich lassen,' and 'Nun ruhen alle Wälder,' and is one of the most beautiful of German chorales. It is introduced by Bach in the Passions-Musik (St. Matthew), in the scene of the Last Supper. (See 'Innsbruck' in Hymns Ancient and Modern.) Whether Isaac actually composed the melody, or only wrote the other parts to it, is doubtful, but it is remarkable that here, as in others of his works, the melody appears in the upper part, which was quite unusual in such compositions. It is in these Lieder that he shows his nationality. In them we have the music which the composer brought with him from his home, the trace of which is not lost in his greater compositions, but blending itself with the new influences of an adopted country, and of Netherland companions, gives to his music a
- Geschichte der Musik, iii. 380–389.