#pianoFader1, #pianoFader2 {
    position: relative;
}

#pianoFader1 IMG, #pianoFader2 IMG {
    position: absolute;
    top: 0;
    left: 0;
    z-index: 8;
    opacity: 0.0;
}

#pianoFader1 IMG.active, #pianoFader2 IMG.active {
    z-index: 10;
    opacity: 1.0;
}

#pianoFader1 IMG.last-active, #pianoFader2 IMG.last-active {
    z-index: 9;
}

.pianoFader1 {

}

.pianoFader2 {

}