TUNELIT

Pitch shift · slow down · loop

Play along in your tuning.

Load a song from your device. It plays in your guitar's tuning, slower if you like, with a loop for the hard part.

Play along · your tuning Beta

Load a song.

Drop a song herePick a song from your device

The file stays on your device. Nothing is uploaded.

MP3, M4A, WAV, FLAC or OGG · up to 60 minutes

  1. Load a songFrom your phone or computer.
  2. Check its tuningThe page listens and names it. Play a little along, then say it sounds right or pick another.
  3. Play alongAny speed from 25 to 150 %, and loop any part.

What it does

Any record, in the tuning you play in

Lots of records are not in E Standard at A 440. Many bands tune down a half step or more, and plenty of older records sit a few cents sharp or flat, because the tape ran a little fast or slow, or the band tuned to a piano or to each other.

Instead of retuning your guitar for every song, retune the song. Load the file: the page listens, names the song's tuning and asks you to say yes. Then it plays shifted into your tuning, so you can play along without touching a peg. Slow it down for a hard part, loop it until it sits, then save the result as a WAV file.

Three steps

  1. Load a song from your phone or computer. MP3, M4A, WAV, FLAC and OGG all work.
  2. Check its tuning. The page measures the recording and names its tuning: E Standard, E♭ Standard, D Standard and so on. Play a few seconds along with your guitar, then tap Sounds right, or pick another.
  3. Play along. Any speed from 25 to 150 %, a loop for the hard part, play mode for the whole screen, and Save as WAV.

For players

Who it is for

  • You keep your guitar in E Standard, and the song is in E♭ or D Standard.
  • You play in Drop C, and want to jam over songs in Drop D or D Standard.
  • You play along with records that sit between the notes: Metallica's Kill 'Em All is about 16 cents sharp on CD, and Pantera's Cowboys from Hell sits near A 435.
  • You learn a fast solo at 50 or 75 % speed, one loop at a time.
  • You teach, and want a song in the tuning your student's guitar is in.

Private

The song stays on your device

Your browser reads the file and does all the work on your phone or computer: decoding, measuring, shifting and saving. Nothing is uploaded, there is no account, and the song is gone from the page when you close it.

After your first visit the page also works offline. A saved file goes to your downloads, named after the song and your tuning, for example Song – E Standard, 75%.wav.

Exact pitch

How the shift works

To change the pitch, the song is resampled with a band-limited filter at an exact ratio. A shift of +8 cents is a ratio of 28/1200, so the result lands on the cent you asked for, not near it.

Resampling alone would also change the speed, like a record played too fast. A phase vocoder stretches the time back: it works on short, overlapping slices of the sound and keeps the frequency of every note. It runs in two bands, long slices for the low notes, so a low B stays steady, and short slices for the highs, so drums and picking stay crisp.

The same stretcher slows a song down to 25 % or speeds it up to 150 % without changing its pitch.

The offset of the recording is measured from its steady notes. In a song in equal temperament every note sits on one grid of half steps, and the distance of that grid from A 440 is the offset. It is measured over 90 seconds from 0:30, so a quiet intro or a spoken start does not count. That measurement cannot tell E Standard from E♭ Standard 100 cents sharp, so the name comes from somewhere else: the tuning list when it knows the song, a link, you, or a guess from the song's low notes (below).

Curious how TuneLit reads pitch in the tuner? How the tuner listens shows its method and its accuracy, note by note.

Check by ear

Why the half step needs your ear

The cents come from the file. The half step comes from a name: yours, a link, or the tuning list, which follows the tabs. Tabs are usually right, but a record that sits near the middle between two notes is easy to name a half step off.

Pantera's Floods is one: the record sits about 64 cents below D, and its best-known tab calls it C♯ Standard. Shifted from C♯, the song comes out a half step too high: E Standard needs about +2.6 half steps, not +3.64.

So when the tuning is only a guess, comes from a link or the tuning list, or the record sits near halfway, the page asks you to check: Hear your low E with the song plucks your lowest open string quietly over it, and Sounds a half step high or low plays the song a half step lower or higher, renaming its tuning from C♯ Standard to D Standard and back.

When nobody named the song's tuning, the page guesses it from the low notes. A bass tuned with the guitars plays nothing below its open string, so the lowest note heard often, with nothing under it, is the low string: E, E♭, D, C♯, C or B. Tested on 189 records it named three songs in four, and 98 % of those were right; when it is not sure it says so and asks you to pick. It hears the low string only, so D Standard and Drop D sound alike to it: for a low D, C♯, C or B it plays the likelier one and asks you to pick between the two. A song that never plays its open low string sounds a half step high to it, so it plays the guess but calls it a guess until you say it sounds right.

When the tuning list knows the song by the file's name but the file sounds a half step or more away (a live take, a cover, or a copy saved here and loaded again), the page shows both answers and asks.

Best sound

Tips

  • Small shifts sound best. A few cents up to about two half steps sound close to the original; bigger shifts and very slow speeds add a soft, smeared sound, mostly on drums and voices.
  • If the measurement says not sure, check by ear: play an open string with the song and move the offset a cent or two.
  • If the song rubs against your open strings by a whole half step, the tuning's name is off, not the cents: use Sounds a half step high or low.
  • A WAV or FLAC file gives the cleanest result. MP3 and AAC files work well too.

Shortcuts

Keyboard

  • Space plays and pauses
  • Esc leaves play mode
  • ← → jump 5 seconds; with Shift, 1 second
  • L loops a part around the playhead, and stops the loop
  • [ ] set the start and the end of the loop at the playhead
  • On a loop handle, ← → move it by 0.1 seconds; with Shift, 1 second
  • On the waveform, Home and End jump to the start and the end (of the loop, when there is one)

Questions

Is my song uploaded anywhere?

No. Your browser reads the file and does all the work on your device. Nothing is sent to a server, and nothing is kept after you close the page.

Does pitch shifting make the song sound worse?

A little, and more the further you go. Shifts of a few cents up to about two half steps sound close to the original. Larger shifts and speeds below about 50 % can add a soft, smeared sound, mostly on drums and vocals.

Why is a record a few cents off A 440?

Many records were made on tape machines that ran slightly fast or slow, or were mastered at a different speed. Some bands also tuned to each other or to a keyboard instead of a tuner. The result can be anywhere from a few cents to a quarter tone away from A 440.

Which files can I open?

Any audio file your browser can play: usually MP3, M4A (AAC), WAV, FLAC and OGG, up to 60 minutes long. Long songs need a lot of memory, so a computer handles them better than a phone.

Can I save the shifted song?

Yes. Save as WAV writes the whole song in your tuning, at the speed you set, as a 16-bit WAV file. It lands in your downloads like any other file.