Untitled

<body>
	<div id="kategorie1">Musik</div>
		<div class="eins">
			<div>- unterelement 1</div>
			<div>- unterelement 1</div>
			<div>- unterelement 1</div>
			<div>- unterelement 1</div>
		</div>
			<div id="kategorie2">Schriften</div>
		<div class="zwei">

			<div>- unterelement 2</div>
			<div>- unterelement 2</div>
			<div>- unterelement 2<div>
			<div>- unterelement 2</div>
		</div>

	<script>

		$("#kategorie1").click(function(){
			// $(".eins").hide();
			$(".eins").css("display", "block");

		});

		$("#kategorie2").click(function(){
			// $(".zwei").hide();
			$(".zwei").css("display", "block");
	   	});

	   	   	$(".eins").css("display", "none");
	    	$(".zwei").css("display", "none");
	</script>
</body>