const scaleHeight = (
        num,
        inMax = Math.max(document.documentElement.clientHeight, window.innerHeight || 0) //viewport height
    ) => {
    const scaleMap = num * 24 / inMax;

    const hertz = ROOT_NOTE * Math.pow(1.059463094359, scaleMap);
    return hertz; 
}

function setNote(freq) {
    // we want oscillator to be initialised when we change it
    if (isPlaying) {
        o.frequency.setValueAtTime(freq, context.currentTime);
    }
}