Plainly put, "Little Child" is not a very good song. Paul has said that he wrote it as album filler for With The Beatles, and the lack of care and interest shows. Despite its thick, sloppy energy - buoyed by John's limber harmonica part, Paul's bustling go on the piano, and Ringo's perky percussion - "Little Child" ends up being something of a nonstarter. In other words, it's a bit boring, a bit routine, and the main culprits are the lyric and the lead vocals. Going in order, the lyric smacks of the kind of safe, predictable, and perhaps hastily completed songwriting that yielded singles for much less inspired acts during those early years of pop. "I'm so sad and lonely/Baby take a chance with me," sings John as he tries to move in on an evidently unconvinced girl. This line typifies the paint-by-numbers vibe of the song. And the vocals can't undo it (neither can the music itself, for that matter). No, The Beatles weren't able to reproduce the trick they accomplished with, say, "Love Me Do:" through memorable song-craft and execution, make a magnetic or even just interesting song around a lyric that leaves something to be desired. Specifically, John's vocal (which appears to be doubled, even though Paul is listed as sharing the lead) is too flat and clipped at times; it feels like a rush-job. And furthermore, there isn't much range to it, undoubtedly due to the fact that the song was originally intended for Ringo. I don't think Mr. Starr would've been a better choice, but it's not as if John made a great song out of it. "Little Child" was likely to be a dud either way.
I'll close with two questions: 1) Am I wrong to find it kind of unsettling that the song's addressee is someone referred to as "little child?" Other parts - "When you're by my side/You're the only one/Don't you run and hide/Just come on come on" - could also rub some the wrong way here in 2010. 2) When John sings "Baby take a chance with me," doesn't it sound just like the melody for the line, "If you want to dance with me," from Chuck Berry's "Rock and Roll Music" (which The Beatles of course covered on Beatles For Sale)?