Rappin Ced is a song from the 2020 Disney/Pixar film, Soul.
As the title suggests, it is performed in the style of rap music and is heard during the part where 22 realizes that Joe Gardner is not Bjorn Börgensson, as Joe looks at holograms of his own lifetime before he ended up as a Soul, looking at a flashback of Joe joining Cedric's rap group on the photo dated on September 20, 1989 (according to the photo) just before Joe and 22 look at a flashback of Joe being taken by his father to listen to jazz music. It is later heard at the end of the credits just before the post-credits scene.
Rappin' Ced is the name, and you should get it right
Blowin' up on the scene like dynamite
Joey G on the keys, KP and Tommy with me (With me)
How much you wanna bet we can take the whole city?
You see us stylin' from the island all the way to BK
Boogie down made the sound, but we took it away
I go to Harlem, it's no problems if you know what I mean
Now everybody bow down to the Kings of Queens
Interestingly, 1989 (the photo that dates back to the moment where Joe Gardner as a teenager dances with Cedric and his rap group) was the year the Pixar short Knick Knack was released.