I would suppose that if 5 or 6 performers turn up presenting as individuals, it would seem only fair they each got their turn, even if the others were backing [ assuming that others joining in was the accustomed practise ] , but not as a band ,plus individually as well.
I remember a band asking for that at an open mic, and the mc quite definitely telling them, that that is not the way it works....not that open mic mc's always share it out equally anyway !.