WHAT IS THIS SONG CALLED? (youtube link provided)?

Question

http://www.youtube.com/watch?v=pOt-zXEzXvI

I love this song, but don't know what it is called. Please Help.

Answer 1

i could only recognise the last piece they played (from 4:00 till the end), it's

One Moment in Time by  Whitney Huston

http://www.youtube.com/watch?v=kGUtbWto0...

(Karaoke version, without vocals)

Answer 2

The second part of the medley  is Summon the Heroes, also by John Williams. It was written for the 1996 olympics.

Answer 3

It is part of the Olympic Fanfare and Theme composed by John Williams for the 1984 Los Angeles Olympic Games.

that theme starts at 1:25 :

http://www.youtube.com/watch?v=K90GoFrLv...

Musician, composer, director.