Super Lydian
Super Lydian is a phrase popularized by Jacob Collier[1] to describe chords with the ♯15 (sharp 15) extension, as well as the scale that gives rise to such chords. The idea behind Super Lydian is that it gets brighter and brighter the further you go up.
Structure
At a basic level, the Super Lydian sound comes from stacking perfect fifths. Stacking them from the root (C-G-D-A-E-B-F♯) results in the set of notes in the Lydian scale. Extending the sequence (C-G-D-A-E-B-F♯-C♯) reveals a new brighter note directly outside of Lydian, commonly referred to as the ♯15. The ♯15 chord-extension is the same note as the ♭9, but always called a ♯15 in the context of the Super Lydian chords.
Other compacted patterns that result in a Super Lydian sound include stacking major and minor thirds from the root (C-E-G-B-D-F♯-A-C♯) and the Super Lydian scale, built from stacking Lydian tetrachords (C-D-E-F♯-G-A-B-C♯).
Super Ultra Hyper Mega Meta Lydian
Extending any of these patterns beyond the ♯15 to reach the “♯19” results in an "Ultra Lydian" sound. Endlessly extending any of the patterns results in what’s referred to as "Super-Ultra-Hyper-Mega-Meta-Lydian"[1].