QMidi Pro is the ultimate MIDI/Karaoke player for the Mac. It can organize and play many types of media files, including MP3, movies, and CD+G, and allows easy text editing/synchronization. It features real-time pitch shifting, time stretching, and the ability to display karaoke and movie content in full-screen mode, even on a second monitor.
Play audio/video and MIDI in sync (requires OS X 10.5 or later).
MTC (MIDI Time code) sync.