At a show or other event, a guest list is a list of people who are allowed to enter the show for free or without a ticket. People on the guest list usually include the press, anyone working in some capacity for the musicians, and if there is space, the friends and family of the musicians and of the people who work for the band.
Being on the guest list is not always the same thing as having an "access all areas" pass or a backstage pass. At larger shows, there are usually two guest lists: a list of people who are to be allowed free entry into the show and a list of people who should be given a backstage pass. It is up to the musicians and the musicians' representatives who ends up on which list.
The number of people that can be granted guest list places is determined in advance of the show between the promoter and the band/band reps. Usually, if a show is sold out, the promoter will be very strict about sticking to the guest list quota out of necessity, but often, if ticket sales are slow, the promoter will be willing to add additional spaces on the night of the show.
Handling the guest list can be a tremendous responsibility. Learn more: