Octaving technique, accomplished by extra pressure on the bag; It is executed through "supporting" - as the koźlarzy themselves express it - the 8th hole, that is, closing it, opening it and closing it again, by hitting the thumb twice, at the same time pressing the bag even more vehemently to get the overblown tone; Sobieska informs us that "octaving" of d¹ results in e♭² (➺ p.121); NB: The term "przedęcie" is a noun; Its plural ("przedęcia" [genitive "predęć"]) is impossible to translate into English (if unavoidable, I would suggest to use "overblown tones").