You may want to take a look at my QuickStart 101 Tutorial.
Basically you could do:
saveAlbum(Album $albumObject)
{
$hydrator = new ClassMethods(false);
$albumArray = $hydrator->extract($albumObject);
// v-- not too sure if that one-liner works; normal if() in case it doesn't
isset($albumArray['id']) ? unset($albumArray['id']) :;
// insert into tablegateway
}