Chris Brown -- Five Shot During Club Appearance (VIDEO)

Chris Brown was onstage at a San Jose nightclub early Sunday morning when gunshots rang out, wounding 5 people ... and it was all caught on video.

Brown was singing at 1:20 AM and the crowd seemed peaceful ... then, suddenly, gunshots ring out, sending everyone including Chris into panic.

Four people were rushed to the hospital and one victim left and showed up at the ER later.

Several people were detained but it's unclear if anyone was arrested.