The notion of a vast and infinitely various tonal repertoire underpinned by the same basic archetype is vital to Schenkerian analysis, but equally important is the idea of coherence and unity within individual pieces. The Ursatz embodies at least two different types of unity: first, there is a thread of continuity from 3ˆ to 1ˆ that theoretically draws a piece into a coherent whole; second, tonal works are unified simply because they are ultimately an elaboration of a single tonic. This second type of unity is perhaps less tangible-it cannot literally be traced through the work like linear unitybut this does not make it any less important to the concept of the Ursatz.