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.

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

Jonathan also testified about cleaning up the rooms which were slick with baby oil and lubricant … telling the court that he fell down twice while cleaning one of the rooms.

Judge Arun Subramanian — spotted hear leaving the court after a long day — has a lot to think about this weekend, too … ’cause he revealed he may dismiss Juror #6 because of questions about whether he’s a New York City resident.