- Acting for Two: A common occurence, but this happens most prominently in the First Era note , due to cast limitations.
- Cut Song: According to Revo, Moira was originally going to be long enough two fill up two CDs entirely, but it had to be pruned down for undisclosed reasons. Even after that, ten more minutes worth of already recorded music had to be cut.
- Fake Nationality: By necessity, usually - Most of the albums are set outside of East Asia, and there's not exactly a surplus of French/ancient Greek/Middle-Eastern/German/etc. singers working in Japan that can sing fluently in Japanese.
- Fan Community Nickname: Fans of Sound Horizon refer to themselves as "Laurants" or "citizens". Their king is Revo himself.
- The Other Darrin: Aramary's absence leaves a lot of empty roles to be filled, so they are replaced by new singers and voice actresses:
- As mentioned above, Michéle Malebranche's role has been filled by Rika Fukami since Roman.
- Chronica appears in Nein, and she is re-dubbed by Miyuki Sawashiro.
- Karen, Fuki, Yura Mari, and Yuuka Nanri reprises Luna Ballad, Stella, the protagonist of "Yurikago", and the protagonist of "Rinne no Sunadokei", respectively.
- Playing Against Type: Remember that energetic fashion show presenter from "Nikushimi wo Hanataba ni Kaete"? That memorable cameo who spouts Gratuitous English and Gratuitous Italian under one breath? The dude is voiced by Sascha. Who? Well, he's appeared in previous albums before, you know. You can easily recognize him by his creepy growl during narrations. Yeah. He's the German narrator.
- Shrug of God: All interpretations are valid.◊
- Teasing Creator: Oh, Revo!
- What Could Have Been: An interview reveals that Revo plans to release Rinne before Nein, which is coined as the 9th Horizon and also for Sound Horizon's tenth anniversary. But with Revo himself being busy with Linked Horizon projects, he ended up dropping on working on Rinne for the time being. He says that if he isn't focused on Linked Horizon projects, Rinne will be released as originally planned.
- What Do You Mean, It's Not Symbolic?: What is Sound Horizon without their symbolisms? Flowers and their associations to womanhood and the fragility of life, the cycle of life and death, the windmill in Roman, the threads of Fate, the change of the seasons, a well and its associations with impulsive desires... Plus the characters' names, and their roles, and practically everything about this band is very ripe for interpretations.
- Word of Dante: There is no such thing as Word of God in the Sound Horizon universe. Revo purposefully makes his stories speculative in nature and never gave any 'official' answers in return because he wants to see his fans' various interpretations for it. As such, if not the manga, fans often rely on the most popular theory for explanation.
Trivia / Sound Horizon