Bowman is excited at the thought that he's going to maybe find out about aliens on behalf of earth.
That keeps him going, though he's lonely.
He plays the sound system loudly and listens to plays and then opera and then only instrumental music.
Heading towards Saturn still.
The novel says no one has noticed that the rings of Saturn are about the age of the human race; it's suggesting that the aliens who gave humans a push up the evolutionary ladder also destroyed some interplanetary object out by Saturn, creating the rings.