I'm trying to alter the getting started app by supplying my own json feed. But I'm having trouble getting it to show up in the list.

Here's my code:

Code:
 launch: function() {
        Ext.create("Ext.tab.Panel", {
            fullscreen: true,
            tabBarPosition: 'bottom',
            items: [
            {
                xtype: 'nestedlist',
                title: 'Songs',
                iconCls: 'star',
                displayField: 'name',

                store: {
                    type: 'tree',
                    fields: [ 'name'],
                    root: {
                        leaf: false
                    },

                    proxy: {
                        type: 'jsonp',
                        url: 'http://phpfakebook.com/songs/get_songs',
                        reader: {
                            type: 'json',
                            rootProperty: 'songs'
                        }
                    }
                },
                detailCard: {
                    xtype: 'panel',
                    scrollable: true,
                    styleHtmlContent: true
                },

                listeners: {
                    itemtap: function(nestedList, list, index, element, post) {
                        this.getDetailCard().setHtml(post.get('content'));
                    }
                }
                    
            },
Here's my json being returned. Now I'm not really sure if my json is correct ( ivalidated the raw json) but I'm unclear how to make it jsonp, so I just wrapped it in a song() function:

Code:
songs({"songs":[{"name":"Chereokee Shuffle","key":"A"},{"name":"Goldrush","key":"D"},{"name":"Big Mon","key":"G"}]})
The feed from the sencha blog doesn't seem to have it's code wrapped in any function, i've tried it both ways but unable to get it to work. I'm sure it's something super simple ....

Thanks, Mark