Most Americans despise tax season. Except maybe accountants, but after trudging through dozens or hundreds of returns, they probably start to hate it too.
If you're working professionally as a musician or have Done The Right Thing as a studio owner (i.e. formed a corporation or similar entity under which your business operates), you can take advantage of all sorts of opportunities to write off expenses and equipment that help you with your craft.
Now, I'm not licensed or capable of giving legal or accounting advice, but there are some things you should certainly discuss with your accountant if you derive part or all of your income from your musical pursuits.
Let me give offer some examples...
Did you buy a new guitar or a new digital recorder? That may be considered capital equipment. What about CDs of your competition, industry magazines, and trade publications? That's almost certainly market research. And gas and toll receipts from traveling to gigs and/or studios? Just one of many forms of performance related expenses. You'll likely find that the invoices from your favorite studio recordings are deductible in some form or another as well.
Depending on how your accountant likes to work, he may suggest that you take deductions and reimbursements from these expenses and purchases in different ways. Large items like a $100,000 mixing console may be amortized over a period of years. An SM-57 purchase, on the other hand, may just get dropped into a virtual bucket with other receipts marked 'Studio' and make their way into an appropriate deduction box on your tax forms.
If you're organized and diligent, you can reap the rewards and save yourself some serious money.