JamBuddy
Music Practice App for Android
Get on Google Play
JamBuddy is a practice app built around readable sheet music. ABC notation renders at whatever size fits your screen—fiddle tunes stay legible even on a phone without scrolling. Add tablature, transpose to any key, play back with MIDI, and edit everything right in the app.
🎼 ABC Sheet Music Rendering
Sheet music scales to fill your screen. The tune displays completely without scrolling.
Scales to fit your screen
The sheet music renderer automatically sizes notation to fill the available space. A two-part fiddle tune displays large enough to read across the room on a tablet, or comfortably on a phone without scrolling. The app only scrolls vertically when necessary to keep the music from becoming too small.
Tablature for fretted instruments
Enable tablature and it appears below the standard notation. Supported instruments:
- • Guitar (standard tuning)
- • Mandolin (GDAE)
- • Ukulele (GCEA)
- • Baritone Ukulele (DGBE)
Tab shows fret numbers on string lines, making it easier to learn pieces if you read tab more fluently than standard notation.
Transpose and change clef
Transpose any tune up or down by semitones—the notation updates instantly. Switch between treble, bass, alto, or tenor clef. Useful when adapting a tune to your instrument's range or matching a recording in a different key.
Choose your instrument for tablature: Guitar, Mandolin, Ukulele, or Baritone Ukulele.
Standard notation with guitar tablature below.
Select your instrument for tablature generation.
Sheet music with Visualization window showing chord positions on the fretboard.
MIDI Playback
Melody
Hear the tune played back so you can learn it by ear or check your reading.
Chords
If the ABC includes chord symbols, play back just the chords to practice soloing or singing over the changes.
Both
Melody and chords together give you a full backing track generated from the notation.
Adjust playback speed from slow practice tempo to performance speed. The tempo slider works independently of any audio files attached to the tune.
Edit any tune
Every tune in JamBuddy is editable. Tap the edit button to modify the ABC notation directly. Fix a wrong note, add chord symbols, change the tempo marking, or rewrite a section. Changes save to your local library.
Add tunes by playing
Use the live transcription tool to capture melodies. Play a monophonic line and watch it transcribe to ABC notation in real time. Edit the result and save it as a new tune in your library.
📱 Three-Window Layout
JamBuddy organizes its features into three main windows. You can show a single window or two windows, arranged in stacked or side-by-side layouts. Each window has a specific purpose:
Tunes Window
Sheet music, audio player, lyrics, and notes
Visualization Window
Circle of Fifths showing notes in the current chord and key as 12 o'clock, current chord's chart, current chord's fretboard view, next chord's predictor, historgram, spectrogram and timeline visualizers
Tools Window
Tuner, metronome, chord chart library, fretboard views, transcription
Tunes and Visualization windows shown together.
Landscape mode gives more room for side-by-side views on some devices.
📚 Tunes Window
The Tunes window is where you browse, view, and practice your music. It has three modes you switch between with tabs:
ABC Display
The primary view. Shows the rendered sheet music with optional tablature. Tap to transpose, toggle tab, change clef, or start MIDI playback. Pinch to zoom if you want manual control over the size.
- • Auto-scales to screen
- • Guitar/mandolin/uke tab
- • MIDI melody + chords
- • Transpose ±12 semitones
Audio Mode
Attach MP3, WAV, or other audio files to any tune, or record directly in the app. The waveform player lets you slow down playback (5%–250%) without changing pitch, set loop points, and save named sections. The built-in recorder captures practice takes or melody ideas that save locally and can be played back in the app or shared as a file saved in the users defined folder.
Notes
A freeform text area for each tune. Write practice reminders, chord substitutions, performance notes, lyrics or anything else you want to remember about the piece.
Notes are searchable from the tune browser, so you can find songs by what you wrote about them.
Thousands of tunes included
Browse, search, and filter your tune library.
Pre-loaded tune collections:
- • Irish Session Tunes – reels, jigs, hornpipes
- • Roaring Jelly Old-Time – clawhammer and fiddle tunes
- • Nigel Gatherer's Collection – Scottish tunes
- • Bluegrass Jam Tunes – bluegrass standards
- • Old-Time Jam Tunes – traditional old-time music
- • Mandozine – mandolin repertoire
- • OpenHymnal – hymns and traditional songs
Add your own tunes by:
- • Pasting or typing ABC notation
- • Importing ABC files
- • Using live transcription
- • Attaching PDFs or images
Filter by key, time signature, genre, or custom tags. Create set lists for gigs.
⭕ Visualization Window
The Visualization window shows what the chord detector is hearing. Tabs let you switch between different views:
Circle of Fifths
The circle rotates so the detected key sits at 12 o'clock. The current chord is shown in the center of the circle and the notes in the chord get circled, showing their relationship to the key. Tap the key on the top bar to lock a key if its know so it stops trying to guess it.
Chord Charts
See fingering diagrams for the current chord on guitar, ukulele, mandolin, baritone uke, or bass. Swipe for alternate voicings. Next-chord predictions show four likely upcoming chords with their fingerings.
Visualization Tabs
Seven views to choose from: Circle of Fifths, Current Chord chart, Current Fretboard, Next Chords predictor, Histogram, Spectrogram, and Timeline. Each shows the detected audio differently to help you understand what's being heard.
Circle of Fifths with detected chord highlighted.
Next chord predictions with fingering diagrams.
🔧 Tools Window
The Tools window contains practice utilities. Each tool is on its own tab:
Tuner
Precision chromatic tuner for any instrument. Shows detected note, cents sharp/flat, and a visual needle. Reference pitch adjustable (default A=440Hz).
Metronome
20-300 BPM with tap tempo. Visual beat indicator. Optional strum patterns for guitar/ukulele practice. Time signatures: 4/4, 3/4, 6/8, and more.
Live Transcription
Play a monophonic melody and watch it transcribe to ABC notation in real time. Edit the result and save as a new tune. Great for capturing ideas or transcribing by ear.
🎵 Real-Time Chord Detection
How it works
JamBuddy uses a CREPE neural network for pitch detection combined with chroma feature analysis. Audio from your phone's mic is processed to identify sounding notes, then matched against chord templates to find the most likely chord.
What you see
- • Chord name (root + quality, like "Am7" or "G")
- • Bass note if different from root (slash chords)
- • Confidence indicator
- • Estimated key from chord history
Detection settings
Adjust sensitivity, confidence threshold, bass boost, and rolling history to match your instrument and room acoustics. Choose which chord types to detect (major/minor only, 7ths, extended) and enable diatonic filtering to prefer in-key chords.
Current chord display with confidence level.
⌚ Wear OS Companion
Circle of Fifths
Real-time chord detection on your wrist.
Chord Charts
Quick fingering reference without reaching for your phone.
Tuner
Chromatic tuner for quick adjustments between songs.
The Wear OS app runs standalone—no phone connection required during use.
👋 About JamBuddy
I'm Steve, the developer. JamBuddy started as a Python tool to match chords to templates via FFT. It became a way to learn Kotlin at the same time as mandolin and eventually evolved into this.
All the features exist because I thought they'd help me learn tunes or play better with others. If you find a bug or need a tweak, you're emailing the person who built it.
No venture funding, no pushy upsells—just a side-hustle app updated after jams and before work.
Get JamBuddy
Available now for Android 12.0+. One-time purchase, free updates.
Get on Google Play