All the musicians on the album "Happy Frame of Mind" posted by Alex are leaders; that's why I'm reviewing it further.
Some of my favorite albums feature Horace Parlan as a sideman on piano with Mingus.
Blues & Roots (Atlantic, 1959)
Mingus Ah Um (Columbia, 1959)
A Modern Jazz Symposium of Music and Poetry (Bethlehem, 1957)
That's where I heard him before.
Here's another tune from that album; solid straight ahead jazz that makes you feel good.
https://www.youtube.com/watch?v=qrjTGPZcyjM