 James illustrates his claim about attention’s link to imagination with an example from Hermann von Helmholtz. This example is an important one for James, and it illustrates some important features of attention that subsequent theorists have tended to neglect. The example involves the variety of attention that needs to be paid when trying to discern the overtones in a note played on the piano. Helmholtz asks us to sit at the piano and to play a G, then, imagining the sound that we have just heard, to play a low C. Doing this, it is claimed, enables one to hear that G is discernibly there (as the third overtone) within the sound produced when C is played. Helmholtz’s claim, which James endorses, is that the kind of attention that is paid when listening for an overtone is constituted by the imagining of what that overtone would sound like. James goes onto claim that there is a wide range of cases in which paying attention to what one is doing consists in this same sort of preparatory imaginative engagement.