Sources

RISM library (siglum) shelfmark of the extant sources of Fontegara (RISM ID no.: 990019546):

Brussels: B-Bc, Conservatoire royal de Bruxelles, Bibliothèque - Koninklijk Conservatorium Brussel, Bibliotheek 27693 part 1. Library (siglum): Brussel, (B-Bc) (see RISM B-VI-1 p.347)
Berlin: D-B, Staatsbibliothek zu Berlin - Preußischer Kulturbesitz, Musikabteilung. Call number: Mus.ant.theor. G 50.
Library (siglum): Berlin, (D-B). Notes: Titelblatt und 1. Textseite fehlen, handschriftlich ergänzt. 2. und 3. Textblatt zusätzlich handschriftlich als Beilage vorhanden. Location: Unter den Linden - Musikabteilung. Provenance: Bibliotheca Landsbergiana. Ludwig Landsberg. Read online
Jena: D-Ju, Thüringer Universitäts- und Landesbibliothek. Call number: 4 Mus.14. Location: INC. Library (siglum): Jena, (D-Ju)
Wolfenbüttel: D-W, Herzog August Bibliothek. Call number: 3.3 Musica. Library (siglum): Wolfenbüttel, (D-W). Hand copy. With [20] pp. of manuscript musical notation (175 variations on a cadence). Read online
Bologna: I-Bc, Museo internazionale e biblioteca della musica di Bologna. Collection Fondo Villa. Library (siglum): Bologna, (I-Bc)
Florence: I-Fc, Conservatorio di Musica Luigi Cherubini, Biblioteca. Library (siglum): Firenze, (I-Fc)
Rome: I-Rc, Biblioteca Casanatense M XIII. 115 3. Library (siglum): Roma, (I-Rc)
Washington, D.C.: US-Wc, The Library of Congress, Music Division. Library (siglum): Washington, D.C., (US-Wc)

Sources 1–4 are listed in RISM series A/I: G 325; all sources (except no. 6, Rome) are listed in RISM series B-VI-1 p. 347.

Brussels
1.1. Info. No scan available?
Berlin
2.1. Info
2.2. Scan info
2.3. Open-access scan
Jena
3.1. Info or permalink
Wolfenbüttel
4.1. Digital library [slow-loading site, sometimes difficult to access]
4.2. Open-access scan
Bologna
5.1. Info
5.2. Open-access scan
Firenze
6.1. Info. No scan available?
Rome
7.1. Info. No scan available?
Washington, D.C.
8.1. Info and open-access scan

Manuscript copy by Friedrich Chrysander (1891, 116 p.) of the Wolfenbüttel (D-W) book, including the 175 manuscript cadences by Ganassi (RISM ID no.: 450035865). Staats- und Universitätsbibliothek Carl von Ossietzky, Musiksammlung M B/2492 (Hamburg). Manuscript; D-Hs M B/2492

Aufgeklebtes Faksimile des Titelblattes einer frühen (Erst?-)Ausgabe mit 3 Flötenspielern, 2 Sängern, an der Wand 3 Gamben und eine Laute, auf dem Tisch 3 Chorbücher [“An attached facsimile of the title page of an early (first?) Edition with 3 recorder players, 2 singers, 3 viols and a lute on the wall, 3 choir books on the table”]
Noten mit Text (“Sheet music with text”)
Teilweise Autograph von Chrysander (“Partial autograph of Chrysander”)
Handschriftlicher Vermerk am Schluß: “Diese Abschrift von Ganassis handschriftlichen Kadenzen habe ich beendet am Sylvester 1891 Abends 9 Uhr” [“Handwritten note at the end: “I have finished this transcript of Ganassis’s manuscript cadenzas on Sylvester [New Year’s Eve] 1891 at 9 o’clock in the evening”]
Erstausgabe: Venedig 1535 [“First edition: Venice 1535”]
Exlibris: “Ex bibliotheca Dr. Fr. Chrysander”

Istituto Centrale per il Catalogo Unico delle biblioteche italiane e per le informazioni bibliografiche - ICCU
Censimento nazionale delle edizioni italiane del XVI secolo (EDIT16)