#define DO 264
#define RE 297
#define MI 330
#define FA 352
#define SOL 396
#define LA 440
#define SI 495

int notas[7] = {DO,RE,MI,FA,SOL,LA,SI};

void setup() {  
for (int i=2; i<9; i++)  
pinMode(i, INPUT);
}

void loop() {    

for (int i=2; i<9; i++)   
{     
while (!digitalRead(i))    
{      
tone (12, notas [i-2]);    
}    
noTone (12);   
}

}