I need to write a business plan for a music management company, does the basic structure change?

Every business plan (and every business) is unique and personal. No two are a like. However, for most businesses, including a music management company, there will be key elements that the audience will expect to see. Granted, some business plan sections will be more important to you than others given your business and industry. But you should still have sections for company overview, management team, market, etc.

Also, the financial considerations of a business plan will still certainly apply. Budgeting, managing cash and assets, tax calculations and projections, etc., will all be important to varying degrees depending on the business itself. But they will also all likely be included in your plan.