Their music is generally in omnibus style; an album contains multiple stories with different themes that create one long, big story. Soprano or mezzo-soprano vocals are mainly utilized. Usage of narration is not restrained. Strong anime influences and applications are apparent in their music; they have started inviting seiyu for narration after their major debut. Their lyrics are very often mysterious and metaphorical, even more so than those of other J-rock musicians, with themes varying from fantastic themes like ancient curse, legend, dream, war, paradise to forbidden lust, longing, obsession, crime, relationship, etc.
There is no constant-running member of Sound Horizon except Revo, the composer. All other support members are different by the albums.