Do not be confused, this is the Madonna version of "Human Nature." It's kind of the forgotten cousin of Youngblood's "Human Nature, Pt. 2" (the Michael Jackson version). Same title, different song; a musical homonym.
This version, contrary to the "Pt. 2" version, is a slow jam that features a soulful trombone solo by Ben McIntosh. Because of the laid back tempo and groove, there's a lot of space for the soloist to explore. But I believe that it's best to take the Count Basie approach: you don't have to play all the notes, only the "right" ones.
If you do feel like exploring, think of Miles Davis' Kind of Blue. Keep your phrasing melodic, and use the tempo and static harmony to build tension through syncopation and logistically resolving non-chord tones. Although virtuosic technique can blow an audience away, soulful playing, on the other hand, will always pull the audience in towards you.
Lastly, the funny quirk about this recording is that it's a big mash-up. It's Madonna's "Human Nature." During bars 4-7 of the trombone solo, he teases Bill Withers' "Just The Two of Us." The vocal backgrounds quote Eminem's "As The World Turns" and Janet Jackson's "Rhythm Nation." Ugh, my head is spinning.
Here's a YouTube video of the Rebirth Brass Band throwing down on "Just The Two of Us." Enjoy!
Recommended Reading: The Real Frank Zappa Book by Frank Zappa. Published by Simon & Schuster.