piano.html

<html>
    <head>
        <title>Piano</title>
        <meta name="viewport" content="width=device-width, initial-scale=1.0"/> 
        <link rel="stylesheet" type="text/css" href="main.css">
        <style>
            .visuallyhidden { 
              position: absolute; 
              overflow: hidden; 
              clip: rect(0 0 0 0); 
              height: 1px; width: 1px; 
              margin: -1px; padding: 0; border: 0; 
            }
        </style>
    </head>
    <body>
        <canvas id='canvas' width=480 height=600 style="background-color:white;">
        </canvas>
        <script src="kontra.js"></script>
        <script src="piano.js"></script>
        <div>Play the piano</div>
    </body>
</html>