So what is a dream sequence?
A dream sequence is a technique used in storytelling, particularly in television and film, to set apart a brief interlude from the main story. The interlude may consist of a flashback, a flashforward, a fantasy, a vision, a dream, or some other element. Commonly, dream sequences appear in many films to shed light on the psychical process of the dreaming character.
… Audio or visual elements, such as distinctive music or coloration, are frequently used to signify the beginning and end of a dream sequence in film. Harvard psychologist Deirdre Barrett points out in the film chapter of The Committee of Sleep that, while the main content of dream sequences is determined by the film’s overall plot, visual details often reflect the indvidual dream experience of the screenwriter or director. For Hitchcock’s Spellbound, Dali designed sharply angled sets inspired by his own dream space, Ingmar Bergman lit dream sequences in several films with a harsh glare of light which he says reflects his own nightmares (though most people’s have dim light), and Orson Welles designed a scene of the trial to reflect the manner in which architecture constantly changed in his dreams.
—It has also become commonplace to distinguish a dream sequence from the rest of the film by showing a shot of a person in bed sleeping or about to go to sleep. Other films show a dream sequence followed by a character waking up in their own bed, such as the dream sequence George Gershwin composed for his film score to Delicious. Certain Surrealist and neo-Surrealist directors such as Luis Buñuel and David Lynch refuse to distinguish between waking life and dreams in many of their films, mixing the two states as they please.
….. Similar to a dream sequence is a plot device in which an entire story has been revealed to be a dream. As opposed to a segment of an otherwise real scenario, in these cases it is revealed that everything depicted was unreal. Oftentimes this is used to explain away inexplicable events. Because it has been done, in many occasions, to resolve a storyline that seemed out of place or unexpected, it is often considered weak storytelling; and further, in-jokes are often made in writing (particularly television scripts) that refer to the disappointment a viewer might feel in finding out everything they’ve watched was a dream.
So I found a couple of expamples that i really liked.
The Big Lebowski – Gutterballs. I really love the exagerated never ending perspectives and how the scenes somehow fit together. There some many subtle or less subtle links to crazy characters, Like the Valkyrie suit also worn is by Elmer Fudd in Bugs Bunny’s Whats up, Doc? (1957)
Spellbound. The Dali backgrounds and sounds work so well and really create a psychedlic feeling.
This Dali surrealism in animation. Destino (2003) The slow movement really make it dreamy.
Kung Fu Pand. The dream sequence is guided by the voice of the maincharacter and the transition between styles at the end guide the viewer back to animation reality.