soundcloud-web-component-application/app/components/sc-player/sc-player.html

<link rel="import" href="../../../bower_components/polymer/polymer.html">

<dom-module id="sc-player">
    <template>
        <style>
            :host {
                margin: auto;
                width: 50%;
                display: block;
            }
        </style>

        <iframe 
            width="100%" 
            height="450" 
            scrolling="no" 
            frameborder="no" 
            src="https://w.soundcloud.com/player/?url={{playlistUrl}}&amp;auto_play=false&amp;hide_related=false&amp;show_comments=true&amp;show_user=true&amp;show_reposts=false&amp;visual=true">
        </iframe>
        
    </template>
    <script>
        Polymer({
            is: 'sc-player', 
            properties: {
                playlistUrl : {
                    type: String, 
                    value: "", 
                    reflectToAttribute: true
                }
            }
        });
    </script>
</dom-module>