Pitch tool
Note ↔ Frequency Calculator
Convert note names to frequency and frequencies back to the nearest MIDI note. Standard A4=440 is the default; orchestral concert pitch can be adjusted explicitly.
440.000Hz at A4=440.0
A4
+0.00 cents from A4 at A4=440.0
How StaveWave keeps this accurate
Pitch, notation, intervals, harmony, and tempo derive from one deterministic music-core module. The test suite checks known answers plus exhaustive invariants so contradictory musical information fails validation instead of reaching the player.