Pepelats – audio looper with drums on Raspberry Pi

USB computer keyboard
MIDI controller with 4 or more buttons sending notes. Connection by BlueTooth or USB

Multiple song parts (intro/verse/chorus/...). Parts have any number of parallel loops
Parallel loops of variable length. Loops play together inside song part unless some of the loops are muted
Quantization, loop's length, start/stop time is adjusted. Example: If a new loop is not exactly 2 bars log it will be truncated or extended with silence.
Full history of undo/redo for each part. When adding new loop all saved undone loops, if any, are deleted – this is the only way to keep it simple.
Parts may be cleared, loops may be deleted on the run. There are two different views for parts and loops.
Silencing, deleting and re-arranging of loops in a part. A loop from the middle may be moved to the end to become the first loop to undo.
Loading, saving of songs. Songs saved along with their drums.
Delay tolerance – allows switching late up to 0.1s
Binary distribution, installation is simple. License is required for full functionality.

Display looper state in attached screen (ex. 3.5" LCD screen) or in a Web browser. Web is preferable as it allows editing configuration. Screen is more convenient if you have small screen attached to looper and do never change configuration.
Control of looper via MIDI or computer keyboard.
User configurable menu files: number of song parts, MIDI commands, etc. Menu is just a text file – you can look to understand what buttons do.

Drum machine with tree drum types: Style, MIDI and Loop
MIDI drum may sync and control external MIDI client, e.g. IOS app. Midi clock is not supported, it may use start/stop, song position, and sys-ex messages to synchronize.
Style patterns and MIDI commands are plain text files easy to edit. Style pattern looks like step sequencer in a text file.
Loop drum uses one song part as drums. It plays along with other parts unless is stopped.
All drums have volume control, random variations and breaks/fills