The publication Musical Instruments of Professor Antonín Modr was first published in 1938 and thus actually belongs to several generations of our musicians - professionals and amateurs. The reason for the unceasing interest in the Blue Book, which has been improved and enriched with new knowledge for years, lies in its comprehensiveness, clarity, comprehensibility and materiality. Modr informs about the development of instrumental genera and individual instruments and of course focuses on their current design parameters, technical and sound possibilities (including data on ranges of notated and sounding, the most advantageous or least advantageous positions) and does not forget about their application in solo and ensemble hre. Numerous examples, overviews, drawings and graphs increase the clarity and comprehensibility of Modro's work. The view of an expert-organologist in Modro's book intersects with the view of a music practitioner. At the same time, the author not only notices the instruments of today's symphony orchestra and wind orchestra, but also pays due attention to the instruments of our and foreign folk music, including instruments that until recently were still considered exotic. In contrast to older editions, some articles on electronic and electronic instruments, which have become obsolete, have been omitted. The development of this group of musical instruments is so rapid in our time that it always requires new special literature, to which we refer our readers.