Coined by David Keenan in the August 2009 issue of the Wire magazine, hypnagogic pop is a broad term covering a constellation of artists that, while having many different "styles", have a similar music making approach: (sometimes extremely) low fidelity production (that is intentional in a different way than that of Lo-Fi Indie) filtering, more often than not, reminiscences of pop culture in various degrees (ranging from transparent, blatant pastiches to nearly abstract filtering, reverbing, often also including Plunderphonics technique) and in different forms (from free-form, even cassette-side-long jams to almost complete copies of pop format, like in the case of Ariel Pink's Haunted Graffiti).

Most often, hypnagogic pop use as starting point 1970s/1980s Pop/Rock, but genres as diverse as Exotica, House, Trip Hop etc. have been used as source. Many of the early artists associated with hypnagogic pop (including James Ferraro) actually belong to a specific American Neo-Psychedelia underground scene, centered around cassette labels such as Not Not Fun Records or New Age Tapes, that can be more often than not simply described with other terms, such as Drone, Noise or Progressive Electronic. However, even these artists have become a lot more transparent and the usage of the term hypnagogic pop has become increasingly relevant.

Even so, it is often confused with Chillwave. Some early chillwave artists, such as Nite Jewel, are borderline cases indeed, but, in time, chillwave has established itself as a full-blown niche with a specific sound, using lo-fi to a much smaller degree than hypnagogic pop, more conventional and accessible song formats (followed with more acclaim, as hypnagogic pop artists are often discarded as being too abrasive), as well as having its own themes and stereotypical sounds. Same notes apply almost entirely to other arguable offshoots, such as Witch House.
Rateyourmusic-core pop.