Michael Jackson's "This is it" can now be heard as a free stream if you want to hear what his first (and most certainly, not the last) posthumous single sounds like.
All the reviews are indicating that it's much better than his more recent stuff: partly because it's an old song but also it seems because Jackson himself didn't produce it. As can happen, he wasn't perhaps the best judge of his own work and it would appear that having other people produce and arrange it has made it better than those albums he did mostly on his own.
Fleshed out this way "This Is It" has the spring and warmth of classic Jackson ballads like 1979’s "She’s Out Of My Life," or "Human Nature" from "Thriller." The melody has a sweet fluidity and Jackson’s vocal ripples with far more feeling than heard on his last few overwrought, and overthought, albums.
While Jackson’s last disc of new material, 2001’s "Invincible," suffered from both mechanical sounding vocals and cold production, "This Is It" leaves more rawness around the voice, to moving effect, and uses its strings as purposeful enhancements, rather than as drenching sweeteners.