Both Uses

theme
in
New Moon
(Edited)

As I spoke, I could hear the distinctive theme music from ESPN's SportsCenter coming from the living room.
Chpt 3 *

theme = associated with a program
I wondered if there was some pirate theme not visible from outside.
Chpt 4 *

theme = unifying idea

Definitions:

(1) (theme as in: theme of the novel)
a basic idea that underlies what is being said or done -- especially in a literary or artistic work
(2) (theme as in: musical theme)
the initial or primary melody of a musical composition

or

(as in "theme song") music that is most repeated in a film, television series, or other theatrical production
(3) (theme as in: wrote a 2-page theme on my summer)
an essay written by a student

(This sense of theme is much rarer in recent decades than in the past.)
(4) (meaning too rare to warrant focus)