In Schenkerian analysis, the bass arpeggiation (German: Bassbrechung) is the bass pattern forming the deep background of tonal musical works.
It consists in scale steps (de: Stufen) I-V-I, each of which may span hundreds of measures of music in the foreground.
[2] The bass pattern is an arpeggiation in the sense that its middle note (V) first arises as the fifth of the elaborated chord (I), of which it is the upper-fifth divider.
[3] It is only when it meets with the passing note of the fundamental line that V becomes an independent chord within the first one.
The bass arpeggiation properly speaking consists in the three scale steps I-V-I exclusively, but it may be elaborated at a remote level: see Schenkerian analysis, Elaboration of the bass arpeggiation.