I have used the word "daydreamish" to describe those aspects of music videos that relate to the effect that music has on how we experience our daydreams.
Naively, one might expect "daydreamish" videos to actually be daydreams.
Except, that's not how it happens.
Sometimes a movie portrays a character's actual daydream. But almost always this has a comedic aspect, for example as in The Secret Life of Walter Mitty.
But this is not how scenes in movies are typically made to be "daydreamish" in a way that interacts strongly with music.
A movie scene or a music video becomes "daydreamish", not by showing us the character's actual daydream, but rather by giving us a strong sense that the character is daydreaming, or at least having thoughts about something that lies outside their immediate reality.
Music videos can also be daydreamish by giving us, the viewers, something to daydream about. This "daydreamable" content can be an activity or situation which we could daydream about doing or being in. It can also be an interaction with a character in the video who is looking directly at us, through the so-called "fourth wall".
(In principle these "daydreamable" types of scenes can occur in narrative movies, but they would usually be regarded as somewhat self-indulgent and gratuitious, since they are unlikely to do anything to advance a plot-line. Scenes where characters are likely to be just "thinking things through" are also not the places that advance plot or add tension, but they are logical intermissions in the flow of a well-told story, and as such they are natural scenes to include in a movie.)
The Volitional Nature of Daydreams
One reason that music videos don't present actual daydreams is that a movie or video can never directly recreate the experience of a daydream.
This is because a daydream, or any thought process that is not a response to immediate reality, is necessarily an act of volition, one which involves a conscious effort to imagine something separate from what is being currently and directly perceived.
So, in principle, a movie can tell us what a particular character's daydream is like (as in the Walter Mitty example I gave earlier), but, a movie can never tell us what it is like to be daydreaming. The most a movie can ever do is tell us what it is like to be in a situation where most people would daydream.
In addition to providing or suggesting motivation to daydream, music videos can also supply motivation to disconnect, at least partially, from immediate reality.
They do this by supplying content which is interesting enough to draw our attention, but which is presented in such a manner as to discourage or frustrate any attempt to fully connect with that content.
These "disconnectional" techniques include fast cutting, slow motion, and various forms of visual degradation.
When disconnectional techniques are applied, the actual content does not represent the daydream, rather it represents immediate reality – because it is this immediate reality that we have to disconnect from if we want to fully experience the emotions of our own daydreams.
As I write this, I feel uncertain about what my conclusion should be.
I believe that there is a definite link between between music and daydreams.
But the link is subtle and indirect. It is almost as if music interacts not with the daydreams themselves, but rather with the prerequisite state of mind, a state of mind that enables daydreams, and enables the emotions in those daydreams to be felt, but which does not necessarily force those daydreams to occur.