Your baby is six weeks old. He keeps awake for longer periods in the day, giving you an opportunity to interact longer with him. You can do a lot to stimulate him and help him develop his faculties.
Speak to him, sing lullabies, play music—from baby rhymes to classical music, anything will do—and you’ll find that he responds by cooing with pleasure and waving his arms and legs. In fact, watching his responses will give you a clue to his musical preferences.