(a fragment of the refrain, sound): http://web.mit.edu/derrict/Public/Music/unknownsong_refrain.mid
(a fragment of the refrain, picture): http://web.mit.edu/derrict/Public/Music/unknownsong_refrain.png
(a bit of the piano solo intro, sound): http://web.mit.edu/derrict/Public/Music/unknownsong_intro.mid
(a bit of the piano solo intro, picture): http://web.mit.edu/derrict/Public/Music/unknownsong_intro.png
I ran into this song four and a half years ago, in some piano+voice songbook that a friend bought in Hong Kong.
I have no clue as to what the song is named, what it's about, what the original instrumentation was, when it was written, where it was written, who wrote it, etc..
I do however remember (1) the exact appearance of the first two bars, (2) the first phrase and plus a bit of the second phrase of the refrain melody, and (3) the refrain's left-hand pattern.
I also remember that the song was in B-flat major, but ended verses in an incomplete cadence in G minor, so that the refrain could begin noticeably in G minor and end up back in B-flat major. I loved this feature.
Interestingly, I later wrote my own song-without-words based on the refrain of this song.
cross-posted to bulby01, chordgasm, music_composers, musictheory, namethattune, songposting; this time, without bothering to type different combinations of these names corresponding to everything BUT the community noted
Edit: mentioned that the intro is instrumenal, not sung.