Currently, Bandsintown does not support events without lineups. At least the headliner field in the event listing is required.
We know everyone loves a good ‘secret headliner’ or ‘special guest’ so we’re working on an update allowing venues to override the headliner field with custom values (i.g., “Secret Lineup”), which will enable venues to type in custom artist names into the headliner field without requiring to select any artist from the database. Watch our Roadmap for upcoming features.