There were songs, some with lyrics, adapted from John Barry's "Theme from
King Kong."
The disco-tinged "Theme from King Kong" was released in December 1976
by Barry White's Love Unlimited Orchestra. There's a single version, and a 12"
extended version.
Composer Lalo Schifrin, best known for writing the theme for
Mission: Impossible (and, my favorite, the Planet of the Apes
TV show theme), included a version of "Theme from King Kong" on his 1976
album Towering Toccata. The cover featured a photo of Schifrin standing
between the twin towers of the World Trade Center.
Andy Williams recorded "Are You In There?" which had lyrics
by David Pomeranz. It was released in June 1976, almost six months ahead of
the film's release.
"Maybe Someday" was written by Alec R. Costandinos and was
recorded by Demis Roussos.
In France, Polydor released a disco tune called "King Kong Is Back
Again,"
by Century Orchestra. The song is credited to Maryland.
Finally, Bobby "Boris" Pickett (known for "The Monster Mash")
and Peter Ferrana released "King Kong (Your Song)" in 1976. While
the lyrics reference the 1933 film, the picture sleeve for the 45 RPM single
featured the '76 Kong.
There are even two demos of the song on YouTube.
And an instrumental version of the song retitled as "Disco Kong."