Not declared in scope

Need help it keeps saying 'not declared in scope' and I am lost at this point, I,ve tried everything to fix it and nothings working
/*
Robot Demo - Example 2
Drive in specific pattern using line counting navigation
*/

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

// 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(left.read());
Serial.print("\t"); // tab character
Serial.print(center.read());
Serial.print("\t"); // tab character
Serial.print(right.read());
Serial.println();

if((left.read() > LINETHRESHOLD) && (center.read() > LINETHRESHOLD) && (right.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
}

it keeps saying 'not declared in scope'

The compiler says a LOT more than that. It says WHAT is not declared in this scope AND it points to where the scope is that the variable is not declared in.

Count your curly braces. The number of { must match the number of }. Yours do NOT match.

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

What an odd place to put a function prototype.
Inaccurate too.

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