The membership profile for your group is often influenced by the conditions that give rise to the group in the first place. Despite these external influences, here are some considerations.
Member Demographics
Junior Corps
Junior Corps are typically ages 10-18. With this age group comes increasing responsibility for supervision, instruction, and a structure that allows the older, more experienced kids to learn leadership characteristics. A Junior Corps is intended to be a safe place for kids to learn about fifing and drumming with people of their own age group, and is by this definition educational and developmental in nature.
Junior Corps require more skilled instructors and a very strong parent network to operate effectively, as most Junior Corps members are not independently mobile.
Senior Corps
Senior Corps are typically ages 18+, and members are generally considered to be responsible for getting themselves to and from corps events. This setting allows novice and experienced adults to participate in a hobby in a decidedly avocational manner.
It was at one time quite common for a Senior Corps to have a junior or “feeder” corps to provide a progression from developmental to avocational participation. This is now, quite sadly, a rare occurrence.
Mixed Ages
In some locations the practice is to keep junior and senior members in a mixed environment from the start. This can be based on the group’s practice, or simple necessity given the limited number of participants. These groups typically follow the structure of Senior corps with juniors added somewhat after-the-fact. This can be challenging for some, as the typical constructs of a junior corps are not present (chaperones, more rigid structure, etc.). In these instances the younger members will often mature a little faster and adapt to the requirements of a mostly adult structure.
Gender
Lastly, while it was at one time common to have gender-segregated corps, it is not recommended that new corps start with this limitation.
Level of Commitment
A key element of understanding the member profile will be the level of commitment expected from the individuals. For example:
A group that regularly competes or performs in large or high profile events will generally rehearse 1-2 times per week and have a set regimen to guide their rehearsal time
A group that plays in a few parades and musters will often rehearse once a week or so, and will likely have a less structured approach
A group that gathers infrequently to play through “the old tunes” for fun may have a completely ad hoc and unstructured approach
All of these approaches are based on the wants, needs, resources available, and decisions of the members. Make sure you clarify your brand and meet the needs of the people you have in the group by understanding what level of commitment you can expect from your members.