Well, that only makes sense – when the Lichtensteiner anthem is played at the Olympics or other international event, they wanted to make sure somebody else stood up! 
“To Anacreon In Heaven”/“The Star Spangled Banner”
“John Brown’s Body”/“The Battle Hymn of the Republic”
“Sweet Little Sixteen,” Chuck Berry/“Surfin’ U.S.A.,” The Beach Boys
“It Must Be Jesus,” The Southern Tones/“I Got A Woman,” Ray Charles
“Yeah Man,” Sam Cooke/“Sweet Soul Music,” Arthur Conley
“The Dance of the Hours,” Amilcare Ponchielli/“Hello Muddah, Hello Faddah,” Allan Sherman
The tune of ‘Islands In The Stream’ by Dolly Parton & Kenny Rogers was reused some years later for Pras & Mya’s ‘Ghetto Supastar’.
How about two songs using the same backbeat? Beyoncé’s ‘Halo’ and Kelly Clarkson’s ‘Already Gone’ were both written by Ryan Tedder and there was a big controversy about how similar they were. Kelly was angry as hers came out second and it seemed like she was copying Beyoncé when she had no knowledge of ‘Halo’ at the time of the recording, and it caused a big public kerfuffle between Kelly and Ryan.
David Bowie’s “Even a Fool Learns to Love” is a loose translation of the song “Comme d’Habitude”. Paul Anka ended up with the “rights” to the song and wrote a new song to the tune, “My Way”. Then “My Way” was loosely translated into Spanish as “A Mi Manera”, still to the same tune.
Bowie later wrote “Life on Mars?”, which has a more different melody, as a sort of parody in response to Sinatra’s popularity with “My Way”.
“Red Wing” and “Union Maid” (yeah, Woody Guthrie did that a lot)
Leonard Cohen’s “Suzanne” and “Hey, That’s No Way to Say Goodbye” sound very similar
BTW, There is an “God rest ye merry Gentlemen” organ solo in the middle of Inna-Gadda-Da-Vida.
Oh wow, man…
Both of these are intentional references, I believe.
The film “How The West Was Won” used the tune for “Come Away With Me.”
Away, away come away with me,
Where the grass grows wild and the wind blows free.
Away, away come away with me,
And I’ll built you a home in the meadow.
In the first case, it might have been intentional or not, but that didn’t save the Men At Work from a massive copyright lawsuit last year.
In the case of Under Pressure/Ice Ice Baby, this is what Hip Hop is based on, taking an existing song/riff and rapping over it. Other examples can be found here.
Last time around my contribution was “Eighties” by Killing Joke and “Come As You Are” by Nirvana. Kurt was a fan of Killing Joke, so this could hardly have been unintentional.
“What’s Up” by 4 Non Blondes is Bobby McFerrin’s “Don’t Worry, Be Happy”.
Actually, the 2nd mvmt of Beethoven’s “Pathetique” Piano sonata.
I was going to say: “Really? Just because they have the same chord structure?” but you are right - the verses are freakishly similar, I never realised that!
Another example: Total Eclipse of the Heart by Bonnie Tyler was reused in the musical “Dance of the Vampires”, also written by Jim Steinman. He also recycled a song from Meat Loaf’s Bat out of Hell II.
Andrw Lloyd Webber is the king of recycling his own music. His most famous song “Music of the Night” started life as Married Man.
[quote=“Mama_Zappa, post:1, topic:556146”]
[li]He’s So Fine and My Sweet Lord (arguably this was subconscious / unintentional).[/li][/QUOTE]
For what it’s worth, I read in Rolling Stone’s issue of the stories behind the top 100 Beatles’ songs that it wasn’t unusual for Paul, George, or John to sit on a song for several months because they weren’t sure if they had unintentionally borrowed the tune. “Yesterday,” I think, is an example of this.