Piano Practice Trainer for MIDI Files

About the Piano Practice Trainer for MIDI Files

Open a MIDI file of a piece and practise it: the notes fall towards an on-screen keyboard, the written notes scroll past in a simple sheet view, and the page hears what you play on a MIDI keyboard, through the microphone or on the computer keys. In wait mode the music stops at every chord until you have found the right keys, so you can work through a passage without the beat running away from you.

It comes with public-domain and Creative Commons piano editions from the Mutopia Project — the Minuet in G from the Notebook for Anna Magdalena Bach, Burgmüller studies, Schumann’s Album for the Young, Für Elise, the first Gymnopédie, Bach’s Prelude in C, Mozart’s K. 545 and The Entertainer — and you can open any MIDI file of your own, from a notation program, a keyboard or a piece you have typeset yourself.

This is a practice tool, not a course: it tells you which notes you missed and where, and keeps a log of what you practised. It does not teach technique, grade you or tell you what to learn next.

Common uses

• Learning a classical piece from its MIDI file, a few bars at a time, with the music waiting for you.
• Practising one hand at a time and then both, at a tempo you can actually play.
• Sight-reading practice: the sheet view scrolls with the beat and the falling notes show which key each note is.
• Checking whether your playing is really getting steadier, from the timing figure and the practice log.
• Practising on a laptop with no instrument at all, on the computer keys.
• Using a MIDI keyboard or digital piano as a practice instrument that keeps track of the notes you miss.

What a MIDI file is, and how to get one

A MIDI file (.mid) holds the notes of a piece — which key, when, how long, how hard — not a recording. That is why this page can slow it down, loop four bars, play one hand or wait for you: it is reading the notes, not stretching audio.

• From a notation program: MuseScore, Sibelius, Finale and Dorico export MIDI from their File → Export menu; LilyPond writes a MIDI file when the score has a \midi block.
• From a digital piano or keyboard: many record to a USB stick as MIDI.
• From an open score library: the Mutopia Project publishes MIDI and PDF for every piece it typesets, under the licences on its licensing page. Its MIDI files come from LilyPond, which does not record an upbeat: for a piece that starts on one, choose its length under Upbeat before bar 1 so the bar lines fall where the printed music has them.
• What will not work: an MP3, a WAV, a YouTube link or a PDF of printed music. Those are sound or pictures, with no notes inside them. This page never downloads music from another site.

Format 0 and format 1 files are read; a format 2 file (separate patterns rather than one song) is explained and refused. Files timed in SMPTE time code are read as well, with their bars counted in 4/4 at 120 beats a minute.

MuseScore, Sibelius, Finale, Dorico, LilyPond and Yamaha are named on this page only to say where files and sounds come from; MySmartCoPilot is not affiliated with their makers.

How your playing is judged

In Play along, every note of the hands you chose is a target. A key counts as right when the same note is pressed within about 200 ms before or 250 ms after the note’s written time — the window people hear as “together”. Press the same key again inside that window and it is a repeat, not a mistake; press any other key and it is counted wrong. A target whose window has passed is missed.

At a slower tempo the window stays the same in real time (it stretches in the music’s time), so playing at 50 % is not made easier or harder than playing at 100 %. Your average offset is reported in milliseconds, timed from the moment each key went down and with the output delay the browser reports for your speakers or headphones taken off (with Bluetooth that report can fall short of the real delay).

In Wait for me nothing is timed. The music stops at each chord and waits; the keys of that chord may be pressed in any order and at any speed, and the page leaves those notes to you (your own keys make that sound). Accuracy is notes played right ÷ (right + missed + wrong keys), the same arithmetic in both modes.

The arrow keys move a run a bar back or ahead within the bars you are practising: the notes from there on are scored again, and the notes jumped over count as missed.

MIDI keyboard, microphone, or the computer keys

• MIDI keyboard (the best way). Plug it in over USB and press Connect (a Bluetooth MIDI keyboard has to be paired in your system’s settings first, and not every system passes one on to the browser). The page uses the Web MIDI API, which Chrome and Edge have on computers and Android, and Firefox on computers (it asks once to add a site permission for MIDI devices); Firefox for Android, Safari, iPhone and iPad do not have it at all. Every key, its velocity and the sustain pedal arrive as played, each with its own time stamp, which is why the timing figures mean something there. A digital piano with its own speakers already sounds: switch off Play the sound of my keys here too so you do not hear every note twice.
• Microphone (where Web MIDI is missing). The page knows which notes are due and asks the sound whether each of them is there, by looking for that note’s harmonic series above the neighbouring semitones and the noise. One note at a time is reliable on a real piano or keyboard; chords are approximate, a noisy room or a second instrument confuses it, and the microphone cannot tell how hard you played. Through speakers the microphone hears the page too, so until you tick I am wearing headphones the page never plays the notes you are practising and ignores any note its own music could explain (the other hand’s notes and their strongest overtones). Nothing is recorded and no audio leaves the page.
• On-screen keys and the computer keyboard. Tap or click the keys; on a computer the lower row (Z S X D C …) and the upper row (Q 2 W 3 E …) play two octaves from the C you choose. Good for learning where the notes are, useless for real technique.

The piano sound is the Salamander Grand Piano (a Yamaha C5 recorded by Alexander Holm under Creative Commons Attribution 3.0), about 0.9 MB of short recordings that load once.

Where the pieces come from, and what their licences ask

The pieces that come with the page are editions from the Mutopia Project. Each of these was either placed in the public domain by its typesetter or published under a Creative Commons Attribution-ShareAlike licence (Mutopia publishes under other Creative Commons licences too). The credits table on the page names the composer and the typesetter of every piece, and links to its page on Mutopia, because that is what those licences ask for.

Share-alike means share-alike: if you pass on one of those editions, changed or not, it keeps its licence and its credit. The public-domain editions carry no such condition. There is no modern pop music here and none can be added: a recent song’s notes are still under copyright, whoever typed them in.

Your own files are yours. They are read in this browser and never uploaded, and nothing about them is stored except the title, the bars you practised and your figures in the practice log on this device.

What the sheet view does and does not do

The sheet view is a reading aid built from the file’s notes: two staves, the key and time signature, bar numbers, noteheads with their stems, flags and dots, accidentals against the key, ledger lines, and a cursor on the beat. Notes that start together are drawn as one chord, and two voices at one moment get their own stems.

It is not an engraved score: there are no beams, slurs, ties, pedal marks, dynamics, triplet brackets or page turns, because a MIDI file does not record most of them and guessing them would be worse than leaving them out. A note value is the nearest written value to the note’s length, so a passage played with a lot of pedal or a detached touch can look odd. For reading practice, print the PDF of the piece from Mutopia and use this page for the sound and the waiting.

Limitations

• A practice tool, not a teaching course: no lessons, no grades, no technique or fingering advice, and no exercises chosen for you.
• No modern songs. The pieces that come with the page are public-domain or Creative Commons editions of classical music; a recent song’s notes are still under copyright, so they cannot be included.
• Firefox for Android, Safari, iPhone and iPad have no Web MIDI, so a MIDI keyboard cannot be used there. Use the microphone or the on-screen keys on those devices.
• Microphone mode is approximate for chords, cannot tell how hard you played, and needs a quiet room with one instrument (and headphones when the page plays the other hand).
• Bluetooth speakers and headphones delay the sound. The timing figure takes off the delay the browser reports, which with Bluetooth can be short of the real one, so wired headphones or the device’s own speaker are better for playing along.
• The sheet view draws noteheads, stems, accidentals and bars — not beams, slurs, ties, dynamics or fingering. Print the piece’s own PDF for proper reading practice.
• A phone shows only part of the keyboard at once (it follows the music), and the on-screen keys are no substitute for an instrument.
• The practice log lives in this browser and keeps the last 300 runs: clearing site data or changing device loses it. Download the CSV once unlocked to keep more.

Privacy

Everything happens in this browser. Your MIDI files are read on your device, what you play is scored on your device, and your practice log is kept in this browser until you clear it. Nothing is uploaded, no account is needed, and the microphone mode records nothing. The page downloads only the piano sound and the piece you choose.