Unchained Melody. (Righteous Brothers is the best!)
Could it Be Magic? (Manilow)
Ready for Love (Bad Company)
Today (an old Jefferson Airplane tune)
Hold Me Now (Thompson Twins)
There are more. And these aren't the sad ones, either.
You can listen to Unchained Melody (not a midi - a wav, I suspect.)
http://www.ladyjayes.com/unchainedmelody.html