In North America, enthusiasts may gather at regularly scheduled, open singing sessions, for example the "chantey sings" held monthly aboard the ship "Balclutha" in San Francisco or weekly in Gloucester, Massachusetts. At these sessions, any participant is free to start up and lead a shanty, which the rest of those present—sometimes over one hundred or more participants—join on the choruses. The gatherings aim for an inclusive atmosphere that welcomes people of all ages, genders, ethnicities, and singing abilities. North American professionals often perform solo or in very small groups, frequently using instruments. Annual maritime festivals in coastal towns provide a gathering point for both amateurs and professionals, and the site for the introduction of new interpretations.