1 - Se?or Staff 0.8.2 Seņor Staff is an open-source music composition application for Mac OS X. It features a staff-based interface (rather than a tracker interface) for natural entry and readability, and supports playback to any MIDI device. Emphasis is placed on user efficiency and automated enforcement of musical constraints. License: Freeware OS: Mac OS X 10.4 Size: 498 KB