Not declared in scope

Kayperkins19:
Need help it keeps saying 'not declared in scope' and I am lost at this point,

Sometimes the first error is not the most important. I fixed a few and there are plenty left. Look at all of the messages and solve the ones you can. Sometimes that will magically fix the first error.

//  Robot Demo - Example 2
//  Drive in specific pattern using line counting navigation

// SparkFun RedBot Library
#include <RedBot.h>

const int LINETHRESHOLD = 300; // UNDEFINED?!?

// create objects using classes in RedBot library
RedBotButton button;
RedBotMotors motors;
RedBotEncoder encoder(A2, 10);
RedBotSensor leftLine(A3);
RedBotSensor centerLine(A6);
RedBotSensor rightLine(A7);

// global variables for buzzer and LED pin numbers
const int buzzer = 9;
const int led = 13;

// global variables to keep track of which scenario to demonstrate
int scenario = 1;
boolean started = false;

void setup() {
  pinMode(buzzer, OUTPUT);
  pinMode(led, OUTPUT);
}

void loop() {
  checkButton();
  if (started == true) {
    if (scenario == 1)
      scenario1();
    else if (scenario == 2)
      scenario2();
    else if (scenario == 3)
      scenario3();
    const int followCountLine();
  }
}

// CUSTOM FUNCTIONS

void scenario1() {
  // Scenario 1: Drive from kitchen to Table 2, drive around table, and return to start
  // drive from Start line to Table 2 line
  followCountLine(2); // 2nd line will be path to Table 2
  pivotAngle(-90); // pivot -90 angle = turn left
  followCountLine(1); // next line is the circle around table
  pivotAngle(-90);
  alertSound(); // food is here!
  followCountLine(1); // drive once around table

  // turn and return to kitchen
  pivotAngle(-90);
  followCountLine(1); // next line is main path
  pivotAngle(-90);
  followCountLine(1); // next line is Start
  alertSound(); // robot is ready for next order!

  // set global variables for next scenario
  scenario = 2;
  started = false;
}

void scenario2() {
  // add code for Scenario 2

  // set global variables for next scenario
  scenario = 3;
  started = false;
  // Scenario 1: Drive from kitchen to Table 2, drive around table, and return to start

  // drive from Start line to Table 2 line
  followCountLine(2); // 2nd line will be path to Table 2
  pivotAngle(-90); // pivot -90 angle = turn left
  followCountLine(1); // next line is the circle around table
  pivotAngle(-90);
  alertSound(); // food is here!
  followCountLine(1); // drive once around table

  // turn and return to kitchen

  pivotAngle(-90);
  followCountLine(1); // next line is main path
  pivotAngle(-90);
  alertSound(); // robot is ready for next order!

  // set global variables for next scenario
  scenario = 2;
  started = false;
}

void scenario3() {
  // add code for Scenario 3

  // reset global variables for 1st scenario
  scenario = 1;
  started = false;
}

void checkButton() {
  // add code for this custom function
}

void alertSound() {
  Serial.print(leftLine.read());
  Serial.print("\t");  // tab character
  Serial.print(centerLine.read());
  Serial.print("\t");  // tab character
  Serial.print(rightLine.read());
  Serial.println();

  if ((leftLine.read() > LINETHRESHOLD) &&
      (centerLine.read() > LINETHRESHOLD) &&
      (rightLine.read() > LINETHRESHOLD) )
  {
    motors.brake();
    playNote(noteA3, WN);
    delay(3000);
    motors.leftMotor(leftSpeed);
    motors.rightMotor(rightSpeed);
    delay(200);
  }
  else
  {
    motors.leftMotor(leftSpeed);
    motors.rightMotor(rightSpeed);
  }
}

void followLine() {
  // add code for this custom function
}

void followCountLine(int target) {
  // add code for this custom function
}

void driveDistance(float distance, int power) {
  // add code for this custom function
}

void pivotAngle(float angle) {
  // add code for this custom function
}

Even with those fixed I'm still getting plenty of errors (and warnings, since I have my warning level set to ALL).

/Users/john/Documents/Arduino/sketch_dec10a/sketch_dec10a.ino: In function 'void loop()':
/Users/john/Documents/Arduino/sketch_dec10a/sketch_dec10a.ino:39:31: warning: type qualifiers ignored on function return type [-Wignored-qualifiers]
     const int followCountLine();
                               ^
/Users/john/Documents/Arduino/sketch_dec10a/sketch_dec10a.ino: In function 'void alertSound()':
sketch_dec10a:120: error: 'noteA3' was not declared in this scope
     playNote(noteA3, WN);
              ^
sketch_dec10a:120: error: 'WN' was not declared in this scope
     playNote(noteA3, WN);
                      ^
sketch_dec10a:120: error: 'playNote' was not declared in this scope
     playNote(noteA3, WN);
                        ^
sketch_dec10a:122: error: 'leftSpeed' was not declared in this scope
     motors.leftMotor(leftSpeed);
                      ^
sketch_dec10a:123: error: 'rightSpeed' was not declared in this scope
     motors.rightMotor(rightSpeed);
                       ^
sketch_dec10a:128: error: 'leftSpeed' was not declared in this scope
     motors.leftMotor(leftSpeed);
                      ^
sketch_dec10a:129: error: 'rightSpeed' was not declared in this scope
     motors.rightMotor(rightSpeed);
                       ^
/Users/john/Documents/Arduino/sketch_dec10a/sketch_dec10a.ino: At global scope:
/Users/john/Documents/Arduino/sketch_dec10a/sketch_dec10a.ino:137:26: warning: unused parameter 'target' [-Wunused-parameter]
 void followCountLine(int target) {
                          ^
/Users/john/Documents/Arduino/sketch_dec10a/sketch_dec10a.ino:141:26: warning: unused parameter 'distance' [-Wunused-parameter]
 void driveDistance(float distance, int power) {
                          ^
/Users/john/Documents/Arduino/sketch_dec10a/sketch_dec10a.ino:141:40: warning: unused parameter 'power' [-Wunused-parameter]
 void driveDistance(float distance, int power) {
                                        ^
/Users/john/Documents/Arduino/sketch_dec10a/sketch_dec10a.ino:145:23: warning: unused parameter 'angle' [-Wunused-parameter]
 void pivotAngle(float angle) {
                       ^
exit status 1
'noteA3' was not declared in this scope