Harpers could be of any age or profession, any sex or gender, and of any race. Humans, elves, and half-elves were most common among them, but a few gnomes, halflings, and dwarves, and even woodland folk like dryads and centaurs also joined. Most members were either rangers or bards, though wizards, rogues, fighters and clerics were also present. Priests could follow any faith; Azuth, Deneir, Eldath, Lliira, Mielikki, Milil, Mystra, Oghma, Selûne, Silvanus, Tymora, and the Seldarine. This caused no issues of faith, though there was some friction with upper ranks of clergy. Druids, particularly of the North, tended to their willing allies rather than members.
The Harpers were led by a council of High Harpers, who were responsible for most of the group's long-term plans and goals. High Harpers were elected through the means of secret ballots among the other High Harpers, with the criteria being long-term service and extreme discretion in the implementation of their plans.