int led_pin1 =2;
int led_pin2 =3;
int buzzer_pin = 11;
struct MusicStruct {  //generating tones
 int A = 550;
 int As = 582;
 int B = 617;
 int C = 654;
 int Cs = 693;
 int D = 734;
 int Ds = 777;
 int E = 824;
 int F = 873;
 int Fs = 925;
 int G = 980;
 int Gs = 1003;
 int A2 = 1100;
 int A2s = 1165;
 int B2 = 1234;
 int C3 = 1308;
 int C3s = 1385;
 int D3 = 1555;
}Music;
struct LengthStruct {
 float half = 0.5;
 float one = 1.0;
 float one_half = 1.5;
 float two = 2.0;
 float two_half = 2.5;
}Length;
int tempo = 400;
void setup() {
 pinMode(led_pin1, OUTPUT); // set led as output
 pinMode(led_pin2, OUTPUT);
 pinMode(buzzer_pin, OUTPUT);
 digitalWrite(led_pin1,HIGH); // and conditions for led
 delay(1000);
 digitalWrite(led_pin2,LOW);
 delay(1000);
 digitalWrite(led_pin2,HIGH);
 delay(1000);
 digitalWrite(led_pin1,LOW);
 delay(1000);
}
void setTone(int pin, int note, int duration) {
 tone(pin, note, duration);
 delay(duration);
 noTone(pin);
}
void loop() {  //putting the buzzer conditions
 setTone(buzzer_pin, Music.B, tempo * Length.one);
 setTone(buzzer_pin, Music.E, tempo * Length.one_half);
 setTone(buzzer_pin, Music.G, tempo * Length.half);
 setTone(buzzer_pin, Music.F, tempo * Length.one);
 setTone(buzzer_pin, Music.E, tempo * Length.two);
 setTone(buzzer_pin, Music.B2, tempo * Length.one);
 setTone(buzzer_pin, Music.A2, tempo * Length.two_half);
 setTone(buzzer_pin, Music.Fs, tempo * Length.two_half);
 setTone(buzzer_pin, Music.E, tempo * Length.one_half);
 setTone(buzzer_pin, Music.G, tempo * Length.half);
 setTone(buzzer_pin, Music.F, tempo * Length.one);
 setTone(buzzer_pin, Music.Ds, tempo * Length.two);
 setTone(buzzer_pin, Music.F, tempo * Length.one);
 setTone(buzzer_pin, Music.B, tempo * Length.two_half);
 delay(5000);
}

EXPANDED TECHNICAL DETAILS

Cinematic Audio Synthesis

This project recreates the magical atmosphere of the Harry Potter "Hedwig's Theme" using the Arduino's precise PWM timing and frequency-to-note mapping.

• Polyphonic Frequency Management: The Arduino uses the tone() function to oscillate a piezo buzzer or high-impedance speaker. The complex, chromatic melody of the Harry Potter theme is stored as a series of constant integer arrays representing frequencies (e.g., $B3, E4, G4$) and rhythmic durations.
• Tempo Control Logic: The firmware calculates the exact "Inter-Note" delay based on the song's triple-meter signature (3/4 time), ensuring the signature "Swing" of the orchestral original is preserved in the 8-bit digital output.

Visual Interaction

• Glowing "Magic" Feedback: (Advanced version) Synchronizes a series of Blue or White flickering LEDs with the melody's pitch; higher notes result in brighter pulses, creating a cohesive audiovisual experience.