:beynah:
my first thought

MJ also wrote and did background vocals for this song by Ralph Tresvant as well.
MJ also wrote and did background vocals for this song by Ralph Tresvant as well.


Also did background vocals for Dave Mason and Kenny Loggins
The Weeknd has an uncredited feature on some R&B song from like 2009 or 2010 but I can’t for the life of me remember who it’s by or what it’s called. I wanna say it’s Ray J but I’m not 100% certain
Supa Cat - Dolly My Baby has the background vocals of Mary J Blige
!https://youtu.be/-u5m_LfiXzM?si=Sp_19-yUzlueTL3Isuper cat don dada
crazy classic
:beynah:
Kendrick on Skyline To
Also did background vocals for Dave Mason and Kenny Loggins
MJ in his Yacht Rock era
Coldplay x Beyonce
that's not a background voice, that's a feature
Both of these songs have backing vocals by David Bowie:


This song has uncredited backing vocals by Scott Weiland:

:beynah:
yeah this is what first came to mind
Girls, Girls, Girls - Q-Tip, Biz Markie & Slick Rick
Girls, Girls, Girls 2 - Michael Jackson apparently
(Edit: apparently MJ vocals didn't make the final cut? His label were weird tbf, remember how they didn't let him sing on The Simpsons but let him do the speaking voice)
He is on the Final Cut. Just tucked far back in the mix. Label politics at the time