<i>once a band reaches profitability, it&#x27;s not customary to go adding 2-3 new members.</i><p>Sure it is, if they want to grow.  Writers, managers, session musicians, stylists, PR people, I could go on.  Just because you don&#x27;t get on stage doesn&#x27;t mean you aren&#x27;t vital to success of a big name band.