Crystal Ball.

Detects guitar chords and combines them into song sheets.

Android

Latest release v0.4

Crystal Ball on screen

Crystal Ball listens to your guitar and tells you what chord you just played. Press Detect single chord, strum, and it names the chord and draws how to fret it — with the chords it nearly picked instead one tap away, and other ways to play the same one further up the neck. Capture a whole part and it becomes a song sheet you can keep, correct and share.

Early-stage release — expect rough edges. Feedback and bug reports welcome via Issues.

Features:

Vocabulary: maj, min, dom7, maj7, min7, sus2, sus4, across all 12 roots. Shapes assume standard tuning (EADGBE).

Honest about accuracy: template matching on clean triads is good, and degrades on a boomy room, a badly tuned guitar, or a phone held across the room. It is a practice aid, not ground truth — hence the runner-up row, which is one tap from correcting it.

Microphone access is required — listening to your guitar is the whole app. Audio is analysed on the fly and never recorded, stored or sent anywhere; the app has no network permission at all.

No ads, no trackers, no network access.