Music that is fixed in a tangible form--sheet music, scores, written notes, any sort of recording, whether analog or digital--is protected by copyright just as other materials are.
First, determine if the music you want to use is in the public domain or available from a licensed resource.
The exemption for classroom use (Section 110 (1)) allows the performance of music in the classroom. The TEACH Act provides for the limited performance of music in the online teaching environment.
Nothing on this guide is to be construed as legal advice. These pages are intended to provide information and guidance in the application of copyright law and to expand on the University of Missouri System Collected Rules and Regulations.
Thanks to Miller Nichols Library of UMKC for permission to reuse material from their Copyright guide.