Middle C is where most people first meet the piano. It sits near the middle of the keyboard and at the centre of the grand staff, the note that bridges the treble and bass clefs and gives a beginner somewhere to plant a thumb. Familiar, central, apparently simple. Its clean identity in one system is C4, the standard scientific pitch notation label, corresponding to MIDI note 60, ringing at 261.626 Hz. That should settle the matter, and in a way it does. The frequency and the MIDI number are fixed and unarguable, the same on every device in the world.

The name, however, is a famous trap. The very same key that scientific notation calls C4 is labelled C3 on Yamaha synthesizers, and some music trackers call it C5. Look at three different machines and you may see three different octave numbers printed against one physical note, which has confused countless musicians trying to line up a part between programs. The resolution is worth holding onto, because it dissolves the confusion completely. The MIDI number never moves.

Middle C is always MIDI 60, no matter what the front panel says; only the octave name on the box changes, a labelling convention that manufacturers never fully standardised. So when two pieces of software seem to disagree about which octave Middle C lives in, they do not actually disagree about the note at all. They are pointing at the same key, at the same 261.626 Hz, and merely spelling its address differently. Trust the number, ignore the name, and Middle C stops being a trap and goes back to being the friendly centre of the keyboard.