OneTaskBy Tim King · Updated
MOD Tempo Changer
Change Mod Speed and Pitch Separately by Semitones, Save as WAV or MP3
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How the MOD Tempo Changer works
Drop a MOD, XM, S3M or IT module and this MOD tempo changer plays it faster or slower and in a different key, with the two settings kept apart. Because a module is a score of notes and samples rather than a recording, the tempo changes without any change in pitch and the key changes without any change in speed. Preview plays the result and Export saves it as WAV or MP3. libopenmpt plays the module inside this tab, so it is never uploaded.
How the MOD tempo changer works
A tracker song plays its rows at a speed set by the composer, and every note triggers a sample at a set pitch. This page scales the row speed for tempo and the sample playback rate for pitch while the module is being played, not afterwards. That is why the result has none of the warbling or smearing you get from time-stretching a finished recording.
Tempo and pitch values
- Tempo (%) scales how fast rows go by. 50 plays at half speed, 200 at double speed, and the New length line shows how long the song will run.
- Pitch (semitones) moves every note up or down. 12 is one octave, so -12 drops the whole song an octave and +7 moves it up a fifth.
Practice and remix uses
Common reasons for changing a module's tempo or pitch
| Goal | Tempo | Pitch |
|---|---|---|
| Learn a fast part by ear | 50 to 75% | 0 |
| Match another track's key | 100% | The semitone gap |
| Chiptune nightcore edit | 125% | +3 to +4 |
| Slowed ambient version | 60 to 80% | -2 to -5 |
Saving the result
Export renders the whole song with your settings in the format you pick under the settings. To mute or solo channels as well, use the MOD channel muter, and to play the original as it was written, use the MOD player.
FAQ
Does changing the tempo change the pitch?
No. The module is played from its notes, so a slower tempo spaces the rows further apart and each note still sounds at its written pitch. Only the Pitch setting changes the key, and it leaves the speed alone, which a plain sample-rate change on a recording cannot do.
Why do some notes sound rough at high pitch settings?
Every sample is played faster to raise its pitch. Short 8-bit Amiga samples recorded at low rates were never meant to go that high, so a large upward shift brings out their aliasing. Small shifts of a few semitones usually sound clean.
Can I change the tempo of just one section?
Not here, since the settings apply to the whole song. Export the full song, then cut the part you need with an audio editor, or edit the speed effects in a free tracker such as OpenMPT, which changes the tempo of single patterns.
Is my module uploaded?
No. The module is played by libopenmpt compiled to WebAssembly and running in this tab, and nothing is sent to a server. Closing the tab clears the module and every render.
See also: all Tracker Music tools, Images, Audio, Video & Screen, PDF, SVG, Simulations & Screensavers, Generative Art, Chart Makers, 3D Model Viewers, Drawing Pads, Mockups & 3D Making, Diagram Makers, 3D Science.
Related tools
MOD Player
Play MOD, XM, S3M and IT tracker modules with a playlist and loop.
MOD Channel Muter
Mute or solo channels of a tracker module and save the result.
MOD To WAV Converter
Convert MOD, XM, S3M and IT modules to WAV or MP3, in bulk.
MOD Pattern Viewer
Watch a module's notes and effects scroll in time with the music.
MOD Sample Extractor
Rip every sample from a MOD, XM, S3M or IT module as WAV files.