I earned a little money on the side performing music for which I received a 1099. I had expenses such as the purchase of music, rental of a keyboard and purchase of a PA system. How do I report my expenses and can I expense the PA system (under $600) or do I need to depreciate it?

As the self employer income that you eanred was les thasn $600, the payer did not have to issue you the 1099; as a general rule, your employer must issue a Form 1099-MISC to you to whom you have paid at least $600 in rents, services including parts and materials, prizes and awards, or other income payments. So as you incurred expenses , you need to deduct those expenses to reduce taxable income. You need to report the income and expenses on sch c. aslongas you used depreciable biz assets,i.e. eqmt or machinery, car etc , then yes you may claim depreciation expenses to reduce your income. You must recapture the depre when you sell them as ordinary income taxed at 25%