Chronium is a sequencer/synthesizer app for creating, recording, and sharing complex melodies simply by a few finger touches.

The main user interface consists of a fingerboard and a control bar. Touch the fingerboard to start, stop, or modify a voice. The horizontal axis of the fingerboard corresponds to different frequencies, similar to a guitar fingerboard. The vertical axis corresponds to different sounds and rhythm patterns which you can configure. When a voice is playing, the corresponding rhythm pattern is shown as a loop around the touch position, along with the red play cursor. On 3D Touch devices (for example iPhone 6S), the pressure applied to the fingerboard affects the sound by changing filter parameters or modulation depths. On other devices, the same parameters are controlled by an estimate of the surface touched by your finger.

The rhythm patterns are produced by thresholding a weighted sum of binary signals. The weights and thresholds can be set using sliders in the pattern editing interface. 7 basic binary signals are available with periodicities ranging from whole notes to sixty-fourth notes. 5 thresholds are used to determine the timing of the notes, the octave, and whether the notes should be accented or not. The weights and thresholds can be set for 3 different locations along the vertical axis of the fingerboard. Patterns in intermediate locations are obtained by interpolating the weights and thresholds.

Up to 7 different sounds can be placed on the fingerboard and sounds in intermediate locations are obtained by morphing between the two nearest sounds. For this app, an advanced virtual analog sound synthesis engine was developed to enable morphing between classic analog and FM synth sounds.

Chronium can record what you play and share it with other apps as a lossless 32-bit audio file. On devices with an A7 processor or higher (iPhone 5S or higher, iPad Air or higher, iPod Touch 6th Gen or higher), you can also record what you are playing as a video and share it on social media, via email, or to the device's camera roll.

Use Audiobus to connect to other apps. Chronium supports Audiobus state saving so you can load and store your Chronium settings directly from the Audiobus app. Furthermore, Chronium settings can be saved to and annotated in the built-in iOS Notes app and shared via email.

What’s New

Version 1.3

Audiobus support

Ratings and Reviews

4.7 out of 5
3 Ratings

3 Ratings

Oceans in space ,

Very intricate IDM beats

Wow, this rhythm layout with circle and patterns is innovative! Visually to see complex poly rhythms turns into a fun game of overlapping parts with time signature mixing. I forget that there is a button on bottom left for infinite note on or off: those 2 modes are different and great. This app is mad hatters and the fact you can record the screen will add to visualize complex beats. There are also melodic fretboard type things and bells and I just use shorter decay sounds for now. Cheers

dataBANG ,

Unique melodic electronic rhythms

It's hard to describe this instrument. But it reminds me of "different drummer" and "shoom". Good for inventing complex techno rhythms on the fly. Sounds even better plugged thru effects.

Obnad ,

Getting better....

I actually think this is a pretty cool app, I'm liking the sounds and rhythms I'm getting from it, but until it adds audiobus/Aum compatibility and ableton link it can't be taken seriously as a creative tool....


Fritz Menzer
2.7 MB

Requires iOS 9.1 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating
Rated 4+
© MN Signal Processing


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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