400 Lonely Things employs a variety of occasional instrumentation but primarily uses obscure sampling to weave mostly instrumental melodic collages of melancholic texture and psychedelic drone. These​ weathered, loop-based introspective forays border on hauntology, dark ambient, experimental, ​electronic, plunderphonics and New Age music.

While 400 Lonely Things is a conceptual project in and of itself, much of their catalog is even more specifically conceptual - with albums reflecting on horror and science fiction and grief and art and (anti)conspiracy and the wistful passage of time. They have released 17 albums - most independently, but also on various labels, along with some split releases and compilation appearances.

Recording began in 1988 between members Craig Varian and Jonathan McCall, using various styles and names until the moniker "400 Lonely Things" arrived in 2002 - which was the same time that this particular thread of music was noticed. Jonathan McCall passed away in 2020, leaving Varian to pilot this cryptic mission of weaponized nostalgia as its sole member. Currently, Varian describes 400 Lonely Things as "Dark New Age for the New Dark Age" which seems close enough.