For professional musicians, instruments are tools of the trade, and their cost is generally deductible. Self-employed musicians can deduct the cost of instruments, cases, strings, maintenance, and other equipment as ordinary and necessary business expenses. Depending on the cost of the instrument, you may be able to deduct the full purchase price in the year you buy it using bonus depreciation or Section 179 expensing. Music lessons taken to improve your professional skills are also potentially deductible when you are already working as a paid musician. Amateur musicians who play as a hobby cannot deduct instrument costs since the activity is not considered a business.