Tetris theme for Arduino with the 16bit timer

tetris.ino

#include <avr/io.h>

void changeFrequency(unsigned int freq)
{
    int ocr = F_CPU/freq-1;
    cli();
    TCCR1A = _BV(COM1A0);
    OCR1A = ocr;
    sei();
}

void setup()
{
    // OC0A - Pin 9 as outout
    DDRB   = _BV(PORTB1);
    TCCR1A = _BV(COM1A0);
    TCCR1B = _BV(WGM12)|_BV(CS10); // CTC, div 1
}

void disableTimer()
{
    TCCR1A &= (uint8_t)~_BV(COM1A0);
}

const int notes[] = {
    1320, 990, 1056, 1188, 1320, 1188, 1056, 990, 880, 880, 1056, 1320, 1188, 1056, 990, 1056, 1188,
    1320, 1056, 880, 880, 1188, 1408, 1760, 1584, 1408, 1320, 1056, 1320, 1188, 1056, 990, 990, 1056,
    1188, 1320, 1056, 880, 880, 1320, 990, 1056, 1188, 1320, 1188, 1056, 990, 880, 880, 1056, 1320, 
    1188, 1056, 990, 1056, 1188, 1320, 1056, 880, 880, 1188, 1408, 1760, 1584, 1408, 1320, 1056, 
    1320, 1188, 1056, 990, 990, 1056, 1188, 1320, 1056, 880, 880, 660, 528, 594, 495, 528, 440, 419,
    495, 660, 528, 594, 495, 528, 660, 880, 838, 660, 528, 594, 495, 528, 440, 419, 495, 660, 528, 594,
    495, 528, 660, 880, 838
};
const int note_len[] = {
    500, 250, 250, 250, 125, 125, 250, 250, 500, 250, 250, 500, 250, 250, 750, 250, 500, 500, 500,
    500, 500, 500, 250, 500, 250, 250, 750, 250, 500, 250, 250, 500, 250, 250, 500, 500, 500, 500,
    500, 500, 250, 250, 250, 125, 125, 250, 250, 500, 250, 250, 500, 250, 250, 750, 250, 500, 500,
    500, 500, 500, 500, 250, 500, 250, 250, 750, 250, 500, 250, 250, 500, 250, 250, 500, 500, 500,
    500, 500, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 500, 500, 1000,
    2000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 500, 500, 1000, 2000
};

#define NOTE_CNT sizeof(notes)/sizeof(int)

void loop()
{
    int i;
    delay(500);
    for (i = 0; i < NOTE_CNT; i++) {
        changeFrequency(notes[i]);
        delay(note_len[i]/1.5);
//        disableTimer();
//        delay(delay_len[i]/1.5);
    }
}