This has always sounded pretty cool to me, C minor to E minor for instance, and it gets a lot of use in film scores (John Williams, Howard Shore, a million others). I happened to be playing the game Dredge recently and it gets used in some incidental music there, as well (briefly going F minor to A minor).
Does anyone know of an early example of this being used in a piece? It seems like it would’ve been first employed by Gustav Holst, or one of the Russians, in the early 20th century, but I’m curious if there is (likely) something earlier than that.