Since July, I've been working my way through the piano book I used in my beginner's piano class in college. Last week I re-learned and practiced "Careless Love," which - according to the book - is a Tennessee folk song. I'm sure I didn't notice this when I first learned the song, but there's a chromatic phrase in the chords at the end of the third phrase and into the fourth:
F7 (F, A, Eb), inverted Bb (F, Bb, D), inverted Bbm (F, Bb, Db), F (F, A, C)
I remember liking that part, but I didn't know it was because of that chromatic phrase (I didn't even know what a chromatic phrase was back then). In the four years or so since I took that piano class, I've learnt a lot more about music, so when I discovered that chromatic phrase now, I realized that it reflects the feeling of the lyrics. There seems to be an inherent melancholy associated with descending chromatic phrases, and the lyrics include a despairing "See what careless love has done to me."
Shortly after I played this song in piano class, I discovered a version by Fats Domino already in my music collection. (For what it's worth, his version is in Ab major where my piano book has it in F major, so the chromatic phrase in his is within the chord sequence Ab7 C# C#m Ab.) I recently listened to it again and transcribed the lyrics. They're different from the ones in my piano book (not unusual for folk songs), but they too have a downhearted feeling, with phrases like "Can’t you see what careless love done to me" and "You said that you love me, and it didn’t mean a thing."