event bind method does not working

[surjit]

I have added below code in controller but it does not works
TypeError: Cannot read property 'on' of undefined

I also tried mediaPlayer insteadof playerName
please suugest playerName comes from, (it seems it's undefined)
$scope.playerName.on( 'load', function( evt ) {
// Tell someone a song is gonna get loaded.
console.log( evt );
} );