controller.js

function LibraryCtrl($scope, LibraryService, artists) { //assumming you're favoring $scope over this
  $scope.artists = artists || []; //defensive
  $scope.albums = [];
  $scope.selectedArtist = null;
  
  activate(); //I like to put my activation logic in a function, and call it
  
  function activate() {
    $scope.selectedArtist = LibraryService.getSelectedArtist();
    
    if ($scope.selectedArtist) {
      //fetch albums
      LibraryService
        .loadAlbums($scope.selectedArtist) //this will persist the results (no point fetching again if the selected artist doesnt change)
        .then(updateAlbums) //resolve value from loadAlbums is probably going to be an array of albums :)
        .catch(handleErrorInView)
    }
  }
  
  function updateAlbums(albums) {
    //update ViewModel
    $scope.albums = albums;
  }
}

service.js

function libraryService($http) {
  var selectedArtist = null;
  var selectedAlbum = null;
  var allArtists = [];
  var albumsForArtist = [];
  
  var svc = {
    getSelectedArtist: getSelectedArtist,
    getSelectedAlbum: getSelectedAlbum,
    loadArtists: loadArtists,
    loadAlbums: loadAlbums,
  }
  
  return svc;
  
  function getSelectedArtist() {
    return selectedArtist
  }
  
  function getSelectedAlbum() {
    return selectedAlbum
  }
  
  function loadArtists() {
    return $http //return the $promise so we can chain/intercept
      .get('/path/to/resource')
      .then(function(response) {
        allArtists = response.data;
      })
      .catch(maybeRetry);
  }
  
  function loadAlbums(artists) {
    return $http //return the $promise so we can chain/intercept
      .get('/path/to/resource')
      .then(function(response) {
        // *** the variable ref albumsForArtist is now pointing to response.data ***
        albumsForArtist = response.data;
        
        return albumsForArtists; // Passing the variable ref back to the controller *** if you change modify it to point to a new object you WILL lose data binding ***
      })
      .catch(maybeRetry);
  }
}

state-config.js

$stateProvider.state({
  name: 'app.lib',
  url: 'lib',
  controller: 'LibraryController',
  controllasAs: 'vm',
  resolve: {
    artists: function(LibraryService) {
      return LibraryService.loadArtists(); //returns $promise, resolve value injected into $controller
    }
  }
})