#include <FastLED.h>

#define LED_PIN     7
#define NUM_LEDS    50
#define BRIGHTNESS  64
#define LED_TYPE    WS2811
#define COLOR_ORDER GRB



CRGB leds[NUM_LEDS];

#define UPDATES_PER_SECOND 100



void setup() {
    
  FastLED.addLeds<LED_TYPE, LED_PIN, GRB>(leds, NUM_LEDS); 
  FastLED.setBrightness(100);
}


void loop()
{
  uint8_t beat1 = beatsin8(30,0 , NUM_LEDS - 1, 0 , 0);
  uint8_t beat2 = beatsin8(30,0 , NUM_LEDS - 1, 0 , 128);
   
  leds[beat1] = CRGB::Blue;
  leds[beat2] = CRGB::Red;
  
  fadeToBlackBy(leds, NUM_LEDS,10);
   
  FastLED.show();  
}