From ASCAP, Using Copyrighted Music:
Are there any exceptions to the requirement to obtain authorization for public performances?
The law provides a few strictly limited exemptions for performances in the course of worship services and performances in the course of face-to-face teaching activities of a non-profit educational institution. Purely non-profit performances may be exempt if (1) there is no direct or indirect commercial purpose; and (2) there is no payment to the performers, promoters or organizers; and (3) there is no admission charge, or if there is a charge, all proceeds after deduction of costs are used exclusively for educational, religious or charitable purposes.