"Rhianna's songs are okay and catchy, but I hear her concerts are really good (hence the great performer comment)."

On Youtube there's clips of her performances and they are nothing special. She sings a couple of words when she feels like it and lets the pre-recorded tracks do the rest. Even her stans in the comments section mention that the concerts weren't great.

It show you've got it (Beyonce) or you haven't (Rihorror).