Tritone. Learn all about the interval called tritone: Tritone is an interval composed of three tones (a augmented fourth or a diminished fifth).
Tritone, Interval, Chord & Harmony
Tritone - Music Theory Academy
Tritone - Music Theory Academy
Tritone substitution - Wikipedia
MTO 12.2: Murphy, The Major Tritone Progression in Recent Hollywood Science Fiction Films
The tritone: The sound of the devil's interval and unlocking how to use it - Blog
The Importance of the Tritone in Harmony - BEYOND MUSIC THEORY
What Is A Tritone In Music?
MTO 12.2: Murphy, The Major Tritone Progression in Recent Hollywood Science Fiction Films
5 Familiar Chord Progressions to Start Any Song – Flypaper