Both volumes contain printed and preserved in the manuscripts, Kolberg’s papers, articles and notes devoted to music, as well as to individuals, institutions and publishers associated with it. Most of the material was published as entries in Orgelbrand’s ‘Encyklopedia powszechna’ [Universal Encyclopedia] in the years 1859-1868; a part was published by Kolberg in musical journals (‘Ruch Muzyczny’, ‘Echo Muzyczne’), and others (mainly ‘Biblioteka Warszawska’, ’Tygodnik Ilustrowany’, ‘Kłosy’); and a part was preserved in the manuscript form, often as fragmentary and draft notes. As many as 1,113 short and long articles that constitute the two volumes concern a vast number of subjects ranging from problems in the field of music theory, its divisions, types and forms, composition and performing, through articles and notes on the history and development of Polish and foreign music, biographies of composers, virtuosi, singers, inventors, creators of instruments, critics and writers on music, to reviews, recollections and notes that refer to current situation in music. This collection presents Kolberg’s achievement in the area of music and musicology, and from the historical point of view, it constitutes a valuable documentation of the nineteenth century state of knowledge. Index of persons, prepared by W. Tomaszewska, which also includes titles of compositions and other works, mentioned outside biographical articles, facilitates in such an extensive material the search for the names of persons associated with music.