440 Lab

Keep a steady beat while you practice. Tap tempo sets the BPM by feel; the first click in each group is accented.

Match the moving beat with Space or a tap. See how early or late you respond and how consistent your timing is.

How timing practice works

Press Play, then press Space or tap as the dot crosses the center line. Match every click, including subdivisions. Results use your latest 20 taps, one per click. Average error measures distance from the beat; bias shows whether you tend to rush or drag. Device latency can affect results.

Read rhythm and pitch from a staff, then sing, hum, or play the phrase through your microphone, or hold Space for each note. You can also drag & drop an SF2 or SF3 SoundFont into this view to use its instruments for playback.

How sheet-music practice works

Choose a clef and perform each note through your microphone. The report compares its start, end, and pitch with the score. Articulate each note cleanly and leave rests silent. You can also hold Space, the button, or the lane for each note; that scores rhythm only. Notes and count-in beats move toward the fixed play line from the right.

Blue guides show the full note duration before it reaches the play line. Red overlays show the time you actually held the input, including early presses, late releases, and holds through rests.

A whole note is hollow without a stem. A half note is hollow with a stem. A quarter note is filled with a stem; an eighth adds one flag, and a sixteenth adds two. When short notes are grouped, one beam replaces each eighth-note flag and two beams replace each sixteenth-note flag. Each value lasts half as long as the one before it.

A curved tie joins consecutive notes of the same pitch across a barline. Attack the first note once and hold it continuously through the tied note.

A dot adds half of the original duration. In 4/4, a quarter note lasts 1 beat, so a dotted quarter lasts 1 + ½ = 1½ beats. A half note lasts 2 beats, so a dotted half lasts 2 + 1 = 3 beats. Rests can have dots too.

Negative milliseconds mean early; positive mean late. Attack and release errors are scored separately. Device and audio latency can affect measurements.

Choose an included MIDI file, attach one, or drag & drop it to visualize it as sheet music. You can also drag & drop an SF2 or SF3 SoundFont into this view to use its instruments for playback. This view supports files with a single time signature; use Tracker for meter changes. This module is a work in progress and is likely to have bugs. Please report bugs at https://github.com/qwell/440lab/issues.

Choose an included MIDI file, attach one, or drag & drop it to visualize it in a piano-roll tracker whose measure lines follow time signature changes. You can also drag & drop an SF2 or SF3 SoundFont into this view to use its instruments for playback. This module is a work in progress and is likely to have bugs. Please report bugs at https://github.com/qwell/440lab/issues.

Hear a reference followed by a mistuned target. Decide whether the target landed flat or sharp.

Recall an unfamiliar melody's exact opening pitch after a delay, or recall a target after interfering tones. No note names or familiar recordings are used.

Listen to the answers and choose the tone that matches the selected note.

Hear a note without a reference and identify its note name. Octave does not affect your answer.

Hear two notes and identify the size of the pitch jump.

Build a requested interval above or below a starting note.

Tuning and reference pitches

Use the tuner to check the pitch of a note with your microphone, or play reference tones to practice matching and tuning by ear. The reference pitch is adjustable, so you are not limited to A440.

Pitch and intonation ear training

Practice hearing small differences in pitch and recognizing whether a note is sharp or flat, identifying a chromatic note without a reference, or identifying the distance between two notes. The exercises develop pitch discrimination, absolute and relative pitch recognition, and a more accurate sense of intonation.

Metronome and rhythm practice

Use the metronome for a steady beat while practicing, choose from common simple, compound, and odd meters, or tap a tempo to set the BPM by feel. Timing practice measures early and late taps. Sheet-music practice generates pitched phrases in four clefs and scores the timing and intonation of notes performed through a microphone.

MIDI playback and visualization

Choose an included Standard MIDI File, attach one, or drop one into the view to play it with a selectable SoundFont, follow synchronized multi-track sheet music, or watch a color-coded piano-roll tracker that follows tempo and time signature changes. Drop an SF2 or SF3 SoundFont into a MIDI or rhythm sheet view to use it for the current session. Seek through the song or mute individual tracks while it plays. Sheet music currently supports files with a single meter. MIDI and SoundFont files are processed locally in your browser and are not uploaded.

Simple by design

440 Lab is designed to be a small, straightforward set of music practice tools: open it, choose a tool, and start practicing. Works well on desktop and mobile.

Headphones recommended

Wired headphones are highly recommended, especially when using the microphone and playing reference tones together. They prevent playback from interfering with pitch detection.

Free forever

440 Lab will always remain free, ad-free, and without in-app purchases. To run this site locally, download and unzip the latest release, which can be hosted on a webserver like nginx or by directly opening index.html.

Get involved

440 Lab is created and maintained by Jason Parker and is open source. If you find a bug or have an idea for an improvement, please open an issue on GitHub.

If you find 440 Lab useful, you can help by starring the project on GitHub or sponsoring its development.