Music Transposition Copyright
<p>So I am designing a mobile app that transposes music for the user. The user can only transpose four notes at a time, and they are required to input the notes themselves. Are there any copyright laws of any kind that might cause problems with my app?</p>

<p>Four notes seems an odd limit, and I wonder if this would be useful to anyone. But that is not the question. If a user types in a copyrighted composition note by note and transposes it, the user may well have infringed the copyright by creating a derivative work. But the app designer and proprietor will not have infringed, unless it was advertised with such a use in mind, knowing that infringing uses were likely.</p>

copyright music