functions.js

document.onkeydown = function(e) {
    switch (e.keyCode) {
        case 48:
            document.getElementById('0').play();
            break;
        case 49:
            document.getElementById('1').play();
            break;
        case 50:
            document.getElementById('2').play();
            break;
        case 51:
            document.getElementById('3').play();
            break;
        case 52:
            document.getElementById('4').play();
            break;
        case 53:
            document.getElementById('5').play();
            break;
        case 54:
            document.getElementById('6').play();
            break;
        case 55:
            document.getElementById('7').play();
            break;
        case 56:
            document.getElementById('8').play();
            break;
        case 57:
            document.getElementById('9').play();
            break;
        case 65:
            document.getElementById('A').play();
            break;
        case 66:
            document.getElementById('B').play();
            break;
        case 67:
            document.getElementById('C').play();
            break;
        case 68:
            document.getElementById('D').play();
            break;
        case 69:
            document.getElementById('E').play();
            break;
        case 70:
            document.getElementById('F').play();
            break;
        case 71:
            document.getElementById('G').play();
            break;
        case 72:
            document.getElementById('H').play();
            break;
        case 73:
            document.getElementById('I').play();
            break;
        case 74:
            document.getElementById('J').play();
            break;
        case 75:
            document.getElementById('K').play();
            break;
        case 76:
            document.getElementById('L').play();
            break;
        case 77:
            document.getElementById('M').play();
            break;
        case 78:
            document.getElementById('N').play();
            break;
        case 79:
            document.getElementById('O').play();
            break;
        case 80:
            document.getElementById('P').play();
            break;
        case 81:
            document.getElementById('Q').play();
            break;
        case 82:
            document.getElementById('R').play();
            break;
        case 83:
            document.getElementById('S').play();
            break;
        case 84:
            document.getElementById('T').play();
            break;
        case 85:
            document.getElementById('U').play();
            break;
        case 86:
            document.getElementById('V').play();
            break;
        case 87:
            document.getElementById('W').play();
            break;
        case 88:
            document.getElementById('X').play();
            break;
        case 89:
            document.getElementById('Y').play();
            break;
        case 90:
            document.getElementById('Z').play();
            break;
        default:
            console.log("Key is not found!");    
    }
};