Access to Class Instance inside TileList and DataProvider?

Question

I have a TileList that is fed by a DataProvider.  The DataProvider places a source Class (and corresponding MovieClip) into the TileList as visual and interactive objects.
     dpChords.addItem({ label:tt, source:ChordUnit, data:i, scaleContent:true }); 
How do I pass unique values to the instances of the "ChordUnit" within the TileList?
public function setChordBin(song:int):void {
          var dpChords:DataProvider = new DataProvider();
          var i:uint;
          // determine chord set
          if (song == -1) {
                    activeChords = allChords;
           else {
                    activeChords = songChordSets[song];
          // fill dataProvider
          for(i=0; i<activeChords.length; i++) {
                    var tt = activeChords[i];
          dpChords.addItem({ label:tt, source:ChordUnit, data:i, scaleContent:true }); 
          chordBin.dataProvider = dpChords;
     // FORMATTING
          chordBin.columnWidth = 105;
     chordBin.rowHeight = 115; 
          chordBin.direction = ScrollBarDirection.HORIZONTAL;
          chordBin.setStyle("contentPadding", 5); 
          chordBin.setRendererStyle("imagePadding", 0);
          chordBin.scrollPolicy  = ScrollPolicy.ON;
          // set style for labels
          chordBin.setRendererStyle("textFormat", textFormat2);
          // set the background skin
          chordBin.setStyle("skin", lightBackground);
          //set the cell renderer
          chordBin.setStyle("cellRenderer", MyTileListRenderer);
    // EVENTS
          chordBin.addEventListener(ListEvent.ITEM_ROLL_OVER, chordBinItemOVER);
          chordBin.addEventListener(ListEvent.ITEM_ROLL_OUT, chordBinItemOUT);
          chordBin.addEventListener(ListEvent.ITEM_CLICK, chordBinItemCLICK);

Answer 1

Here is the "" Class:
package {
          // associates to "ChordUnit" MC graphic in library
          import flash.display.*;
          import flash.events.*;
          import flash.net.URLRequest;
          public class ChordUnit extends MovieClip {
               public var imagePath:String;
               public function ChordUnit():void {
                    loadDiagramImage(imagePath);
               public function loadDiagramImage(imagePath:String) {
                    trace (imagePath)
                    var request:URLRequest = new URLRequest(imagePath);
                   this.diagramView.scaleContent = true;
                    // this.diagramView.addEventListener(Event.COMPLETE,loadComplete);
                    // this.diagramView.addEventListener(ProgressEvent.PROGRESS,loadProgress);           
                    this.diagramView.load(request);
Of course, without being able to pass a unique "imagePath" value into the Class instance, the trace is "null".