Having a problem

I’m trying to make music play, then have an led light up for 30 seconds and then have a servo spin, and then 30 or so seconds later another servo spin. Whenever the code executes the music plays and the servo runs at the same time.

#define LED_PIN 13
#include <CytronEZMP3.h>

CytronEZMP3 mp3;
#include <Servo.h>
Servo nose;  // cont run rt servo to spin robot:
int pos =0;
Servo spin;  // cont run rt servo to spin robot:


void setup() {
  pinMode (LED_PIN, OUTPUT);


  Serial.begin(9600);
  if(!mp3.begin(2, 3))
  {
    Serial.println("Init failed");
    while(1);
  }
  mp3.setVolume(25);
  Serial.print("Device: ");
  Serial.println(mp3.getCurrentDevice()==1?"U-Disk":"microSD");

  Serial.print("Total files: ");
  Serial.println(mp3.getTotalFiles());
  
  
  nose.attach(8); // attaches servo to pin


  spin.attach(3);
}


void loop() {
 music();
  delay (3000);
 LED_sun();
  delay (3000);
 spin2019();
  delay (3000);
 nose2019();
  delay (3000);
 exit(0);

}
void music() {
  mp3.playTrack(1);
  Serial.println("Now playing track 0001" + (String)mp3.getTrackNo());
  delay (6000);
  exit(0);
}
void LED_sun() {
  digitalWrite (LED_PIN, HIGH); // Turn on the LED
  delay (30000); // Wait one second (1000 milliseconds)
  digitalWrite (LED_PIN, LOW); // Turn off the LED
  delay (3000); // Wait one 
  exit(0);
}
void spin2019() {
  spin.write(180);
  delay(30000);
  exit(0);
}
void nose2019() {
  nose.write(0);
  delay (300);
  exit(0);
}

What do you think that exit(0) does?

groundFungus:
What do you think that exit(0) does?

Will the result/program behavior be different if return is used instead of exit(0)?

GolamMostafa:
Will the result/program behavior be different if return is used instead of exit(0)?

Yes.

GolamMostafa:
Will the result/program behavior be different if return is used instead of exit(0)?

Whandall:
Yes.

@OP
If you call a sub-function from the loop() function, the control goes to the sub-function; the codes are executed and then the control goes back (return) to the loop() function. There is no need to write the return keyword explicitly at the end of sub-function; it is understood.

You are calling nose2019() sub-function from the loop() function. Having finished the sub-function, the control should be reverted to loop() function.

Look at the above question/answer and then think if you are returning to loop() function or not due to the inclusion of exit(0) at the end of your nose2019() sub-function.