In this penultimate chapter about air instruments “whose only function is to cause the air surrounding them to vibrate,” Schaeffner pursues the idea that components of ancestor instruments led to later instruments, rather than later instruments acquiring more components. Could it be, asks Schaeffner, that the double oboe is in fact the oldest form of the instrument, the single oboe having detached itself from the double oboe later on? Armed with this hypothesis, he suggests, in the genealogy of air instruments in this chapter, the following approximate sequence: “reed—cavity or tube of whistle, flute or horn—clarinet—double clarinet and double oboe—oboe.” Thus Schaeffner’s argument leads us first from the ground and body up, then outward to the immediate spatial environment of the musician, who becomes distinct from the instrument itself but remains essential for creating resonance by exploiting the instrument’s cavities.