My wife plays piano for several churches, if we get a new piano can we deducted some or all of it from our taxes?

Does she receive paid compensation for playing the piano at these churches?

Yes, she is compensated at both churches 

Yes

If she receives $400 or more during the year in compensation then she is self-employed and must file a Schedule C with your personal tax return.

Any items she buys for use by the business can be entered as an expense.  However, if the item can be used for both personal use and business use then only the percentage of business use can be deducted from the self-employment income.

IRS website for self-employed individuals - https://www.irs.gov/businesses/small-businesses-self-employed/self-employed-individuals-tax-center

Thank you!  I now need to ask the question slightly different as my wife corrected me.  She is actually employed by both churches.  Does that change the deduction process?

if she gets w-2's (ie she's an employee) - the cost of the piano neither in whole or in part is deductible

Thank you for your information!