That song is called THE LAST LEAF. It was written by Bodie Chandler and Edward McKendry in 1963, and recorded by The Cascades. It's on an album called "The Very Best of the Cascades."

If you look up the album on Allmusic.com (you might need to register to do this, but it's a very valuable resource if you do a lot of music research) you can play a sound sample that begins with…guess what?...the bridge!

You might be able to find the same sound sample on other web sites. I'd look more, but I gotta run.