We have 12 members - we cannot have more because of the space and positioning of our speakers. Our members each take one afternoon and present a project - a specific period, composer, type of music, etc. We also have several meetings a year where we all join in and present a piece of music related to the topic chosen - seasons of the year, time of day, earth, water, fire, air, forests, Desert Island disc, specific country, time ,etc. etc. The idea is listening and learning so some people do not present a whole afternoon, those of us who have more knowledge of music will do this and share our knowledge and interest.
Obviously a second group may have different ideas and would not have to follow ours, but I could give help and ideas for them to start if they wanted. You also need good equipment and a room large enough for several people.