What are bylaws?
Your orchestra needs bylaws. Bylaws define your organization's structure and will be needed for your 501(c)(3) nonprofit application and possibly for starting a bank account.
Bylaws contain information defining your mission, purpose, objectives, activities (broadly speaking), membership, the structure of your board and officers, conflict of interest and non-discrimination policies, and legal jargon necessary for nonprofit organizations. Bylaws define the structure of your organization, not detailed policies or things that might change often. After you initially adopt them, you should not have to change your bylaws unless the fundamental structure or purpose or activities of your organization change. Creating your bylaws is a chance to thoroughly think through what you want your organization to be.
Your board and/or your membership should vote to officially adopt your bylaws, and you should review them periodically after that. The bylaws should spell out the method for updating the bylaws in the future.
When creating bylaws for the RCO, I wrote them up myself after looking at several examples and then reviewed them with my board members section-by-section during a meeting. When the final draft was ready, I sent them out to the orchestra membership for review, and several people did actually take the time to read them and provide feedback. This method worked fine for us.
You are welcome to use the RCO's original bylaws as an example and to copy and paste as much of the text as you like for your own organization. You might also be interested in viewing the Dexter Community Orchestra's bylaws (a group I used to play in and run, though I did not write their bylaws). I recommend looking at several sample bylaws before finishing yours.
Some special considerations
When creating the RCO bylaws, I added some specific things designed to avoid certain future problems I anticipated. I will describe some of the decisions I made here.
I chose to explicitly define the duties of every board member in the bylaws, rather than leaving the number flexible and the duties vague. I didn't want the orchestra to be weighted down by people who serve on the board in name only and don't actually contribute anything meaningful. For the same reason, I included a clause stating that board members could be removed from office by a vote of the other board members for failure to adequately perform their duties or for engaging in activities harmful to the organization. I did not want us to get stuck with an officer who didn't wasn't pulling his weight with no way to get rid of him until the next election. It is possible that we might end up amending the number and duties of the officers described in this section more frequently than I would like as our activities change and the duties of the officers solidify (since we're still figuring out all the work that has to be done), but changing duties and activities seem like things that should warrant a bylaw review anyway. You can read a fuller discussion about my decisions for structuring the board elsewhere.
I put a clause in our bylaws that specifically forbids the orchestra from compensating musician members for playing in the orchestra. If, at some point in the future, the orchestra's leadership wants to pay members for their services, this would be a fundamental change to the mission and purpose of the organization, so the bylaws would have to be amended, and amendment is done by a vote of the musician members themselves. This prevents an overly-ambitious future leader or music director from deciding to convert the organization to a "professional" orchestra against the desires of the orchestra's members. I have known of a few other groups that started as community groups and later converted to professional or semi-professional groups. While the quality of music they produced went up, they became inaccessible to many musicians who wished to play in them and ceased to be "community" orchestras. If this type of progression is your goal, that's fine, but if it isn't, I recommend adding some blockages in your bylaws.
Some things I purposefully left as decisions for the board. My board decided that we would not charge membership dues, but we didn't think a future decision to charge dues should warrant a change to the bylaws. Consequently, the bylaws state that membership dues will be determined by the board. Similarly, the bylaws state that the music director and any guest artists can be either volunteers or paid (and neither category can be a voting member of the organization).