Diddy‘s trial got the whole courtroom buzzing Friday … but, it had nothing to do with testimony — it was all about the arrival of another music legend.

Kanye West showed up at Friday morning … drawing a tons of eyes — and quite a few cameras — as he dapped up Diddy’s son Christian on the way into the courtroom.

However, Ye left the trial after only about 10 minutes … even though court officials opened up a whole other overflow room just for him to watch the proceedings.

As for the action inside the courtroom Friday … Jonathan Perez — one of Diddy’s former assistants — was the star witness, and he talked about setting up the room for “king nights.” King nights are the name Diddy’s staff gave to the infamous freak-offs.

Perez testified that he put a series of products — including honey — inside the rooms where the action happened.