My mandarin is too terok to rebutt you..but yes you are right..it means to "act and sing".
When I attend a concert, I wish to hear the singer's live performance as opposed to audio recordings..If it is a rock act concert, to rockz on together..!

What the other antics that the artistes use to work up the crowd are bonus points.
By the way, going by the logic of your reasoning...when I ask my colleagues whether want to go 'chi fan' together..does it mean iterally that we can only 'eat rice' together?? I meant it to be "let's go for a meal together!!"
No wonder we have been having chinese food for lunch these days..

juz a lame joke