One of the leading theories on Scriabin's late music proposes that members of the same set class are related primarily through invariant transposition. Whereas this theory is effective in relating symmetrical collections such as the octatonic, it cannot relate asymmetrical collections such as Scriabin's mystic chord. This presents the question: can the concept of invariant transposition be expanded to relate asymmetrical collections? Based on Scriabin's frequent reference to his collections as keys (tonalnosti), this paper explores how an invariance relationship between closely related keys -- maximally invariant transposition -- extends into Scriabin's post-tonal music. Maximally invariant transposition maintains the same transpositional relationships as invariant transposition, while applying to asymmetrical collections. This theory reveals that Scriabin's late music possesses series of closely related transpositions marked by disruptions through distantly related transpositions.

Viewing Scriabin's late music through the lens of key relationships brings about a new appreciation of his late music. Rather than a static progression of dissonant chords, his music becomes a series of exotic keys weaving in and out through a series of smooth transpositions. This theory also challenges the notation of a clear break with tonality in Scriabin's late music by demonstrating a connection between his tonal and post-tonal periods through key relationships.