I like the folk clubs I go to and they all have similar formats. A mixture of singers/musicians nights and paid guest nights. The paid guest nights typically vary from fortnightly to monthly. Singers/musicians nights are mostly round the room singaround format with an MC to manage the evening. Usually you sing or play from your seat but in some cases you go up to the front and sing. Mostly either one or two songs each time. You don't seem to get residents in the old sense and the "support" on a guest night is round the room with some or all of those who sing getting one song each and just once round in total. The guest usually gets two 40 - 45 minute spots.

With a good MC the whole thing works well and those I know are very fair.