Many of the letters concern the theatre in Scotland, discussing relationships between theatre companies and playwrights, and the possibility of producing plays in Scots. Robert McLellan's own work and that of his correspondents is a major topic, and the writers include figures such as the actor Duncan Macrae, and the playwrights Alexander Reid, Donald Mackenzie and Ena Lament Stewart. There are numerous letters to McLellan from amateur companies, requesting permission to produce his plays. The correspondence also reflects Mclellan's other interests in poetry, the history and local affairs of Arran, and bee-keeping.