I had income as a band musician (2 years of profit followed by 2 years of loss) I now work alone doing weddings. Is this considered the same business? This isn't a hobby.

I have invested in an elaborate sound system in 2016, thus creating another year of loss.  If I report another loss, the IRS may consider my business a hobby and disallow all expenses.  This is not a hobby.  It is only similar to the 4 prior years in that it is still work as a musician, but the structure is different.