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Accura Overview

Accura is the intonation module. Given a PitchContour (from PitchDetection) and a tonic, it grades how accurately the singer hit the target intervals of a tuning system, returning per-note deviations and an overall 0–100 score.

FacadePurpose
Accura.analyzePitchingPer-note deviation analysis against EQ or JI
Accura.calculateScore0–100 score from an analysis result

Accura wraps the lower-level PitchAnalysis. Use Accura when you want a tuning-system-aware grade; use PitchAnalysis when you just want a raw histogram or transcription.

Quick Start​

val extractor = PitchDetection.createContourExtractor(ContourExtractorConfig.SCORING)
val contour = extractor.extract(audioSamples, sampleRate = 16000)
extractor.release()

val result = Accura.analyzePitching(
    contour,
    tonicHz = 196f,                          // G3
    intonationSystem = IntonationSystem.EQ,
    scaleIntervals = listOf(                  // optional: explicit scale targets
        TargetInterval(0f, "S"),
        TargetInterval(200f, "R2"),
        TargetInterval(400f, "G3"),
        TargetInterval(700f, "P"),
        TargetInterval(900f, "D2"),
    ),
)

if (result.error == null) {
    val score = Accura.calculateScore(result)
    println("Score: ${score.score}/100 (${score.tier}) over ${score.noteCount} notes")
}

Failure semantics (ADR-022)​

KindHow it surfacesCaller action
Caller bug (empty contour, tonicHz <= 0, empty scaleIntervals)IllegalArgumentExceptionFix the call site
Domain-level inconclusive (valid input, but < 3 histogram peaks, no target intervals match)Non-null IntonationAnalysisResult with error != null and empty notesCheck result.error and degrade gracefully

calculateScore requires result.error == null and a non-empty notes list — pass an inconclusive result and it throws.

See also​