I was looking at sheet music for Scriabin's Sonata No.2 in G-sharp Minor, and came across this interesting notation I'd never seen before. The piece is written in three-halves time signature. I was wondering if someone could explain what this is and how to play it.
They should be played together. They're just spaced oddly like that to accommodate the presence of both E and E#.
The reason it's E and E# (as opposed to, say, E and F) is because of the previous E-F# dyad. For the notation in question, the E is a repeat of the previous E, and the E# is the lower neighbor to the F#s on either side.
Looking at it as two separate voices, one voice sings E-E, and the other voice sings F#-E#-F#.