Duration and the Plica. Plainchant in Spain during the Fifteenth Century and the first half of the sisteenth century Kathleen E. Nelson

**Describe the concern** A clear and concise description of what the concern is. **To reproduce** Steps to reproduce the behavior: 1. Go to '...' 2. Click on '....' 3. Scroll down to '....' 4. See error **Expected behavior** A clear and concise description of what you expected to happen.