West Side Story is an American musical written in the mid-1950s by a team of Leonard Bernstein (music), Steven Sondheim (lyrics), and Arthur Laurents (story). Roughly, it is an adaptation of Romeo and Juliet to the mean streets of contemporary New York. The Highlander is an American film from 1986 directed by Russell Mulcahy and starring Christopher Lambert, Sean Connery and Clancy Brown. It is a fantasy action story revolving around immortals who can only be killed by decapitation.
Doesn't seem like an obvious place to find a connection, does it? Here are the lyrics to the West Side Story song "Somewhere":
There's a place for us,
Somewhere a place for us.
Peace and quiet and open air
Wait for us
There's a time for us,
Some day a time for us,
Time together with time to spare,
Time to look, time to care,
And the lyrics from the Highlander song "Who Wants to Live Forever":
There's no time for us
There's no place for us
What is this thing that builds our dreams
Yet slips away from us
Who wants to live forever?
Who wants to live forever.....?
There's no chance for us
It's all decided for us
This world has only one sweet moment
Set aside for us
Very similar, even beyond the parallel phrases "There's a place for us/There's a time for us" against "There's no time for us/There's no place for us". What's more, the songs are used at similar plot points. In West Side Story, "Somewhere" comes when Tony and Maria have fallen in love, but realize that if they stay in New York, gang culture will conspire to make their relationship impossible. In Highlander, "Who Wants to Live Forever" comes when Connor MacLeod, an immortal, is watching his mortal wife Heather grow old and die. He realizes finally that their love is tragically doomed, no matter where they go.
Beyond the similarity of lyrics, the music is also reminiscent. I googled for influences on Brian May (who wrote "Who Wants to Live Forever") and couldn't find anything leading me to think he was a West Side Story fan. But it's not exactly an obscure reference, either. Could it be that May was thinking of West Side Story when he wrote the song?