 In his second phase, which he held from the early 1870s to the early 1890s, Brentano introduced the notion of original association. A mental phenomenon does not disappear from consciousness from one moment to another, it is rather retained for a short period of time. When I hear a melody a, b, c, d, for example, I first hear a. When, in a second moment, I hear b, a still persists in my consciousness, but is modified as “past”. When, another moment later, I hear c, both b and a are retained in original association; now also b is given as “past”, while a is “pushed back” even further into the past, as it were, etc. In this way, Brentano can explain how the melody (as a whole) can be the intentional object of a mental phenomenon: in each moment, the present and the (very) recent tones are given, but the latter are not given in the same way (or else we would not hear a melody, but we would hear all the tones at once; we would, in other words, not hear a melody, but a cacophony). The tones that are past are given with temporal modifications – which do not further determine them, but rather modify their ontological status from real to not real. In this period Brentano holds that two presentations can differ only in the object towards which they are directed; the continuously changing temporal moment, thus, is a modification of the objects. An object that sinks back into the past undergoes, according to this view, continuous modifications.