Calibra
Offline note/exercise evaluation for scales, arpeggios, and svara patterns.
What is Note Evaluation?
Note evaluation scores how accurately a student performs individual notes in a sequence. Unlike melody evaluation (which compares complete phrases), note evaluation scores each note separately.
Use it for:
Scale practice: Sa Re Ga Ma Pa... with per-note feedback
Arpeggio exercises: Broken chord practice
Interval training: Jumping between specific notes
Svara patterns: Indian classical music exercises
When to Use
| Scenario | Use This? | Why |
|---|---|---|
| Evaluate scales/exercises | Yes | Per-note scoring |
| Evaluate complete songs | No | Use CalibraMelodyEval |
| Real-time scoring | No | Use CalibraLiveEval |
| Just detect pitch | No | Use CalibraPitch |
Quick Start
Kotlin
val pattern = ExercisePattern(
noteFrequencies = listOf(261.63f, 293.66f, 329.63f), // C4, D4, E4
noteDurations = listOf(500, 500, 500), // 500ms each
notesPerLoop = 3
)
val studentContour = pitchExtractor.extract(studentAudio, 16000)
val result = CalibraNoteEval.evaluate(pattern, studentContour, referenceKeyHz = 261.63f)
println("Score: ${result.scorePercent}%")
result.noteResults.forEach { note ->
println("Note ${note.noteIndex}: ${note.scorePercent}%")
}Swift
let pattern = ExercisePattern(
noteFrequencies: [261.63, 293.66, 329.63], // C4, D4, E4
noteDurations: [500, 500, 500],
notesPerLoop: 3
)
let studentContour = pitchExtractor.extract(audio: studentAudio, sampleRate: 16000)
let result = CalibraNoteEval.evaluate(
pattern: pattern,
student: studentContour,
referenceKeyHz: 261.63
)
print("Score: \(result.scorePercent)%")
for note in result.noteResults {
print("Note \(note.noteIndex): \(note.scorePercent)%")
}Key Transposition
When students sing in a different key than the reference:
Kotlin
val result = CalibraNoteEval.evaluate(
pattern = pattern,
student = studentContour,
referenceKeyHz = 261.63f, // Reference in C
studentKeyHz = 277.18f, // Student sings in C#
leewaySamples = 100 // Allow timing flexibility
)Platform Notes
iOS
Audio must be 16kHz mono; use SonixDecoder/SonixResampler to convert
Use
@ShouldRefineInSwiftmethods with provided Swift extensions
Android
Audio must be 16kHz mono; use SonixDecoder/SonixResampler to convert
Works with any pitch contour from CalibraPitch
Common Pitfalls
Wrong audio sample rate: Audio must be 16kHz; use SonixResampler if needed
Mismatched note count: Pattern and student must have same number of notes
Forgetting key transposition: Set studentKeyHz if student sings in different key
See also
For complete melody/song evaluation
For real-time evaluation during singing
For defining note patterns
For understanding evaluation results
Functions
Evaluate with configuration object.
Evaluate with preset.
Evaluate a note/exercise performance.