Financial questions that need an answer

Here’s the scenario. Can I attract a potential amateur musician to become an executive producer on my band’s project if he is listed as a partner in our LLC and therefore he can write off all of his musical instrument purchases (home studio , guitars, amps etc.) off his taxes. At that point he is no longer an amateur. He has prefabricated an investment in our business and we will do our best to turn him a profit on his investment. Does this seem like a viable and legal plan?