Arduino Code 

#include "Adafruit_PM25AQI.h"
#include
#include "pitches.h"

SoftwareSerial pmSerial(2, 3);
Adafruit_PM25AQI aqi = Adafruit_PM25AQI();

const int speakerPin = 11;

// definying the melody
int melody1[] = {NOTE_C2, NOTE_C3, NOTE_A1, NOTE_A2, NOTE_AS1, NOTE_AS2};
int melody2[] = {NOTE_C3, NOTE_C4, NOTE_A2, NOTE_A3, NOTE_AS2, NOTE_AS3};
int melody3[] = {NOTE_C4, NOTE_C5, NOTE_A3, NOTE_A4, NOTE_AS3, NOTE_AS4};
int melody4[] = {NOTE_C5, NOTE_C6, NOTE_A4, NOTE_A5, NOTE_AS4, NOTE_AS5};
int melody5[] = {NOTE_C6, NOTE_C7, NOTE_A5, NOTE_A6, NOTE_AS5, NOTE_AS6};
int melody6[] = {NOTE_C7, NOTE_C8, NOTE_A6, NOTE_A7, NOTE_AS6, NOTE_AS7};

int durations1[] = {4, 4, 4, 4, 4, 4};
int durations2[] = {4, 4, 4, 4, 4, 4};
int durations3[] = {4, 4, 4, 4, 4, 4};
int durations4[] = {4, 4, 4, 4, 4, 4};
int durations5[] = {4, 4, 4, 4, 4, 4};
int durations6[] = {4, 4, 4, 4, 4, 4};

void setup() {
Serial.begin(115200);
while (!Serial) delay(10);

Serial.println("Adafruit PMSA003I Air Quality Sensor");
delay(1000);

pmSerial.begin(9600);

if (! aqi.begin_UART(&pmSerial)) {
Serial.println("Could not find PM 2.5 sensor!");
while (1) delay(10);
}
Serial.println("PM25 found!");

pinMode(speakerPin, OUTPUT);
}

void loop() {
PM25_AQI_Data data;

if (! aqi.read(&data)) {
Serial.println("Could not read from AQI");
delay(500);
return;
}

Serial.println("AQI reading success");
Serial.println();
Serial.println(F("---------------------------------------"));
Serial.println(F("Concentration Units (standard)"));
Serial.println(F("---------------------------------------"));
Serial.print(F("PM 1.0: ")); Serial.print(data.pm10_standard);
Serial.print(F("\t\tPM 2.5: ")); Serial.print(data.pm25_standard);
Serial.print(F("\t\tPM 10: ")); Serial.println(data.pm100_standard);
Serial.println(F("Concentration Units (environmental)"));
Serial.println(F("---------------------------------------"));
Serial.print(F("PM 1.0: ")); Serial.print(data.pm10_env);
Serial.print(F("\t\tPM 2.5: ")); Serial.print(data.pm25_env);
Serial.print(F("\t\tPM 10: ")); Serial.println(data.pm100_env);
Serial.println(F("---------------------------------------"));
Serial.print(F("Particles > 0.3um / 0.1L air:"));
Serial.println(data.particles_03um);
Serial.print(F("Particles > 0.5um / 0.1L air:"));
Serial.println(data.particles_05um);
Serial.print(F("Particles > 1.0um / 0.1L air:"));
Serial.println(data.particles_10um);
Serial.print(F("Particles > 2.5um / 0.1L air:"));
Serial.println(data.particles_25um);
Serial.print(F("Particles > 5.0um / 0.1L air:"));
Serial.println(data.particles_50um);
Serial.print(F("Particles > 10 um / 0.1L air:"));
Serial.println(data.particles_100um);
Serial.println(F("---------------------------------------"));

// Determine which melody to play based on the particle count
if (data.pm25_env < 5) {
playMelody(melody1, durations1, sizeof(melody1) / sizeof(int));
} else if (data.pm25_env < 10) {
playMelody(melody2, durations2, sizeof(melody2) / sizeof(int));
} else if (data.pm25_env < 15) {
playMelody(melody3, durations3, sizeof(melody3) / sizeof(int));
} else if (data.pm25_env < 20) {
playMelody(melody4, durations4, sizeof(melody4) / sizeof(int));
} else if (data.pm25_env < 25) {
playMelody(melody5, durations5, sizeof(melody5) / sizeof(int));
} else {
playMelody(melody6, durations6, sizeof(melody6) / sizeof(int));
}

delay(1000); // sensor delay
}

void playMelody(int melody[], int durations[], int notes) {
for (int thisNote = 0; thisNote < notes; thisNote++) {
int noteDuration = 650 / durations[thisNote];
tone(speakerPin, melody[thisNote], noteDuration);

int pauseBetweenNotes = noteDuration /** 1.30*/;
delay(pauseBetweenNotes);

noTone(speakerPin);
}
}