I love the internets. I'm watching the movie "Brief Encounter" on TCM. A scene occurs that has the lonely woman walks the streets, I hear a familiar song. Very sad. It sounds so much like "All By Myself" by Eric Carmen. So I went to Wikipedia to look up "Brief Encounter" found that the song playing is Piano Concerto No. 2 by Rachmaninoff. I found out the song's melody was indeed used for the melody of "All By Myself"