/* pick some random artists */
function pickRandomArtists() {
    var pickedArtistsCount = 6 + Math.floor(Math.random() * 6);
    var artistElements = document.getElementsByClassName("checkbox-artist");
    for (var i = 0; i < pickedArtistsCount; i++) {
        var random = Math.floor(Math.random() * artistElements.length);
        artistElements[random].click();
    }
}