TMZ claims that a few armed men took Usher and Rich's associates by storm, pistol whipping violently at least one bodyguard.
A man opened fired and possibly as many as 10 shots were fired as he ran away from the studio. He was outside the studio when it went down and multiple shots were fired.
As the two were standing outside of the Westlake Recording Studio in WeHo preparing for a recording session, a group of gunmen rolled up on the entertainers and Rich's entourage.
Police are now searching for suspects.
Rich the Kid reached No 2 in the United States charts a year ago with his debut album The World is Yours, which featured the hit single Plug Walk.
As TMZ points out, Rich had posted a photo holding a wad of cash earlier in the day. It's unclear if anyone was hit when the shots were fired, but the suspect (s) "made off with a ton of cash and jewelry". "For motivational purposes only", he captioned it.