Did anyone else notice this, or am I out of my tree (don't answer that)?

All right, so I've been meaning to make mention of this, but somehow I keep forgetting: Last weekend, I finally saw Seven Pounds, the Fresh Prince's latest blockbuster, and I noticed something that I'm wondering if anybody else noticed: Without giving the plot line away, there's this scene in which our hero, Mr. Smith, is finally about to consummate his relationship with his lovely female co-star, and there's a piano interlude that's playing. During the sequence I kept hearing a sour note that made me wince. It was like finger nails on the ... well, you know the rest. If you've seen the movie did you happen to notice this? (Sweetie didn't, even after I rewound the movie a half dozen times.) Well, I did, and it made me crazy, which is probably why I kept rewinding the damn thing. It bothered me so much that I googled the words, "sour note" and "Seven Pounds." The only relevant result I came across was this review in the Providence Phoenix, that both confirmed my suspicion and also co-signed the conclusion that I had reached -- that the sour note was intentional and was being used as an unspoken narrative device (she refers to it as a subtle metaphor) meant to convey the notion that as idyllic as the circumstances seemed on the surface, there was a forboding undercurrent of ruination. Who knows? Maybe good ole Betsy and I are both wrong. Maybe somebody just forgot to tune their piano. Or, I don't know, maybe I just spend too much timing thinking about this kind of stuff.