(SPOILER AHEAD!)
Baby is “a good kid and a devil behind the wheel”. But after being coerced into working for a crime boss, he must face the music when a doomed heist threatens his life. Morality, speed and sound are the main themes in this picture. We know other pictures similars like “The Driver” (1978) and “Drive” (2011).

MORALITY
When Baby was a kid, a car crash gave him tinnitus, and so the music helps him drown out the ringing in his ears. But David Sims notes in The Atlantic (here), “Right from the opening shots, Baby is doggedly trying to block out the nasty mayhem around him (in addition to his tinnitus). … Baby’s habit of recording conversations he overhears (one that eventually gets him into trouble) feels like a similar way of blinkering out the bleakness.”
According to Gracy Olmstead from “The Federalist”, the movie “Baby Driver” is similar to the book “Crime and Punishment” (here). Raskolnikov commits murder to prove that the elite can transgress moral codes in order to achieve some larger utilitarian good:
In “Baby Driver,” Baby’s (Raskolnikov) confession follows the same pattern: Deborah (Sonya) compels him to give himself up to the police. During his trial, testimonies to his kindness and good character save Baby from a harder sentence. Baby works in prison for the duration of his sentence, and is then released—finally free to be with Deborah.
SPEED AND SOUND

Speed and Sound. Velocity and Music. Speed describes only how fast an object is moving, whereas velocity gives both how fast it is and in which direction the object is moving. The movement of an object. Baby distinguish himself for the speed that he drives.
Also, Baby is a character that has tinnitus, a deaf guardian, and he’s always listen to music (great soundtrack included). The sound is a mechanical wave that results from the back and forth vibration of the particles of the medium (air, water, solid objects, etc) through which the sound wave is moving. The movement of particles.
Baby is surrounded by the elements of the movement, covered in a sphere that protects himself of the violent world and circumstances that has damage his life.
Was he slow?