A practice room for blues
Tell it how long you have. It builds the session, shows you what to play, listens through your guitar, and scores what you actually played — both how fast you can play it and how well you remember it.
What it does
A session that knows what you need
Warm-up, memorisation, licks, playing over changes, ear training. Every session carries something you know, something you are learning, and something new — and the licks, the changes and the ear work are all built around the shape you just drilled.
It hears you play
Note by note: right pitch, and whether you were on the beat. Green means you got it, red means you did not, and it tells you what you played instead.
Two kinds of progress
Speed and memory are tracked separately, because you can have a shape memorised cold and still be slow at it. The tab fades as you learn; the metronome moves when you earn it.
Play over the changes
A synthesised rhythm section or a real backing track, with a fretboard that follows the chord and points at where to land when it turns over.
Record what you come up with
It writes your playing out as tab and keeps the audio too. Carve the good bits into licks and practise them later.
Play what you hear
It plays a phrase; you sing it, then find it. The part that turns theory into something you can actually use on the bandstand.
Getting it listening
Best is a wired signal: a USB audio interface, or one of those guitar-to-USB cables sold for Rocksmith. Those put an analogue-to-digital converter in the plug and send the dry signal straight to the browser. A microphone works too — it is just noisier, and it hears the room.
The pitch detection runs on an audio worklet. Chrome and Edge are the most predictable; Safari mostly works; nothing on iOS will see a USB interface.
Use the badge at the top right. Your browser will ask for microphone permission once — a USB interface counts as a microphone as far as the browser is concerned. In Settings you can set the input level and the noise floor while watching the meter.
Worth two minutes. Every audio path has a delay, and without measuring yours the app will think you are consistently early. You play along with a click for a few bars and it works out the offset.
Only matters if you are using a microphone: a backing track coming out of speakers goes back into the mic, and the app tries to score the record.
What it cannot do
One note at a time. Chords and double stops are not scored — it hears a single line. Arpeggiate and it is happy.
Bends are approximate. A bend is a continuous slide in pitch; the detector reports discrete notes, so it will read the destination if you get there and something odd if you do not.
Clean tones work best. Heavy distortion muddies the harmonics the pitch detection relies on.
Very fast passages merge. Above roughly sixteen notes a second, separate picks stop being separable.
Your playing
Everything stays in this browser. There is no account, no server storing your practice, and no audio leaving your machine — the pitch detection runs locally, on your device.
That cuts both ways: clearing your browser data clears your progress, and a different browser or machine starts empty. Settings has an export you can keep somewhere safe.