Chord Player
Play a song and see its chords, key and tempo in time with the music – big enough for the whole class on a projector, or for a family sing-along at home. Then play along, slow it down, make it easy, or move it into a key that suits your voice.
Classfern listens only to work out the chords, on this device. Nothing is recorded, saved or sent. The microphone or the computer’s sound starts only when you press a button, and stops when you press Stop or leave the page.
How it works
- Choose how it listens. Scan first, then play gives the best results: Classfern listens to the whole song, works out the beat and the chords, then plays the song back with the chords exactly in time. Live is for jamming: chords appear as the music plays, about a beat behind.
- Pick the sound. Open a song file from this device (MP3, WAV, M4A or OGG), listen with the microphone, or listen to this computer’s sound – for example a song playing in another tab.
- Play along. The big chord is the one to play now, with the next chord and a count of the beats until it changes. The circles light up on every beat (beat 1 in yellow).
For the class: projector mode
Press Projector mode for a huge current chord, the next chord, a beat light and a chord diagram, readable from the back of the room. Space starts and stops, the arrow keys jump a bar back or forward and Esc leaves projector mode.
- Chord diagrams for guitar, ukulele, keyboard and chime bars or coloured tuned percussion tubes (the same note colours as Classfern’s colour notes: C red, D orange, E yellow, F green, G teal, A blue, B purple).
- Easy chords turns every chord into the nearest of I, IV, V and vi, so beginners can join in with four chords.
- Roman numerals (I IV V vi) and numbers (1 4 5 6, the number system many session players use) show how the song is built.
- Transpose moves the chords up or down a semitone at a time; capo shows the guitar shapes to play with a capo.
- Slow down a song file to 50–90% – the pitch stays the same in most browsers and the chords stay in time.
- Play with Classfern beats: drums, bass and chords play the chart at the song’s tempo, in any of the backing-track styles. Loop it in Backing tracks sends the song’s main chord pattern to the metronome and backing tracks page.
Tidy and keep your chord charts
Press Tidy the chords to change a chord, split or join chords, move a change a beat earlier or later, say where bar 1 starts, or set the key. Save in this browser keeps the chart on this computer; Download chart gives you a small file (chord names and beat times only, never any sound) that you can open again on any computer with Open a chart file. You can also type chords in yourself.
Listening to this computer’s sound
In Chrome and Edge on a Windows PC, Mac or Chromebook, Classfern can listen to a tab that is playing music: press Listen to this computer’s sound, choose the tab and tick Share tab audio. On Windows you can share the whole screen with Share system audio instead. Only the sound is used – the picture is switched off straight away. Safari, Firefox, iPads and phones can’t share sound with a web page: use the microphone near the speaker, or open a song file.
Good to know
- The chords are worked out by computer, on this device, with music rules (no AI service and nothing sent anywhere). They are a good first draft, not a transcription checked by a musician.
- Best results: a clear recording with guitar or piano chords, and Scan first. A microphone picks up the room too, so in a noisy classroom hold the device near the speaker. Busy jazz chords, heavy distortion and a loud singer over quiet chords are harder.
- Chords are shown as major, minor, 7th, sus and diminished chords; choose Full under Chord detail to see maj7 and m7 chords too, or Simple for major and minor only.
- Only use music you are allowed to play to your class. Songs are never fetched or stored by Classfern.
Questions teachers ask
Is my music uploaded anywhere?
No. Classfern listens only to work out the chords, on this device. Nothing is recorded, saved or sent. A song file stays in this page’s memory so it can be played back, and is gone when you close the page. Only the chord chart is kept, and only if you save or download it.
How accurate are the chords?
On clear recordings of pop, folk, rock and carols with guitar or piano, most chords are right, and the timing follows the beat. It finds major, minor, 7th, sus and diminished chords (and maj7 and m7 on the Full setting). Busy jazz harmony, heavy distortion, a loud singer over quiet chords, and a microphone in a noisy room make it less reliable. Treat the chart as a good first draft and use Tidy the chords to fix anything.
Can it listen to a song playing in another tab, such as a video?
Yes, in Chrome and Edge on a Windows PC, Mac or Chromebook: press Listen to this computer’s sound, choose the tab that is playing and tick Share tab audio. Safari, Firefox and phones can’t share sound with a web page, so use the microphone near the speaker or open a song file instead.
What are Roman numerals and numbers for?
They show each chord’s place in the key (I, IV, V, vi or 1, 4, 5, 6), so the class can play the same song in any key and see the patterns that thousands of songs share.
What does Easy chords do?
It swaps every chord for the nearest of the four most common chords in the key (I, IV, V and vi). Beginners can play along with almost any song using just four chords.