The main theme of this movie: Attention to detail.

Rating: 9/10 (4 February 2018)

This review will have no spoilers because all that needs to be said about this movie is in the first two sequences.
In the opening scene we see the two most important themes of this film, Cars and music. Then we get all the backstory we need. Baby is a lighthearted kid that appreciates music and is happier without the crew. He doesn't exactly fit in because he doesn't like the violence. We also learn that he knows what he is doing. One person from the crew points forwards, but Baby drives in reverse because we saw a cop going the other way in the background. Then we get a sequence of well-shot, practical effects car chase scenes. All of this timed perfectly to the music too, every door shut, every break slam, every turn. All of this backstory is given to us without a single word of exposition. All we get is action and detail.
Then after being stunned by the perfection of that sequence we are put directly into another scene that is just as good, if not better.
Baby is walking through the city listening to music. Every piece of graffiti or character movement matches up to the lyrics of the music. When he finally arrives to get coffee, we get the first words of exposition and it is only to inform us that his name is Baby. Then we see that as he turns back to return to the crew, things are no longer happy. He has to avoid a cop, a bike, and a car. This is all in one long tracking shot, where even the sound effects were timed perfectly with the music.
In these two scenes we see what this movie is really about: attention to detail. Throughout the film every sound effect is timed with the music, every scene is a practical effect, and every detail tells us more about the characters. We even see in the end that these details return and help Baby, though I won't reveal too much. The movie isn't timed to the music just because it is cool. I think the movie does this because it really draws everyone in and tunes them into the movie's subtle details. Everyone watching this movie gets captivated and really falls for the tricks this movie pulls, every joke, every twist, every beat.
The movie doesn't feel like a music video, but more like a subtle musical. The ones where you go and sit in the audience and are drawn in by the music. You watch the entire play as if it were a film and don't realise until the end that music was a major part of the play. In this film the music is a large part of the film that draws you in, but during the movie it really feels like more of a side point or a returning joke. The real main attraction is the perfection of every scene, the amount of attention put into detail. The movie feels smooth and ironed-out. The movie feels as if it were rewritten and refilmed hundreds of times until finally, the movie was perfect to them. It may not be perfect to you, but to Edgar Wright and the other creators of this film it is a masterpiece, and I agree.
Edgar Wright is a master of detail and he has shown this in all of his movies. This movie is no exception. Many people didn't like it because of the story, which wasn't perfect, but I still believe that if you really disliked the movie it is because you weren't paying enough attention.