Qie Stem Slicer
User Manual

GUI Overview

IMPORTANT: If you just want stems from Qie, and don't care about creating perfectly segmented 8 bar loops for your library, then all you need to do is hit the Process Audio button. Otherwise continue on and learn the GUI.

1. Track Title Value

This defaults to the name of the file you dragged in. You can choose to overwrite this, especially if you don't want a very long name for your 8 bar loops folder.

2 + 3. BPM Value + BPM Change Selector

After you've loaded a track, the BPM Value is filled in automatically. If the track exists in your Rekordbox library, Qie uses Rekordbox's BPM directly (see Rekordbox Integration). Otherwise, Qie runs its own BPM analysis. This value can be overwritten and will be labeled on every stem and loop segment.

The BPM change section is a 3 way toggle that lets you choose one of three BPM adjustment values: +/-1.0, +/-0.1, or +/-0.01 (which you can cycle between using hotkey Shift + Left or Shift + Right).

Hitting Shift + Up or Shift + Down will change our BPM Value (2) by the BPM change amount.

4. Key Value

After you've loaded a track, the Key Value is filled in automatically. If the track exists in your Rekordbox library, Qie uses Rekordbox's key detection (see Rekordbox Integration). Otherwise, Qie runs its own key analysis. This value can also be overwritten. By default we write out the Western Key as well with Camelot Wheel notation.

5. Hot Key Overview

Click on 5 to take a look at the global hotkeys that are used to control many other UI components. Memorizing this will allow you to identify the BPM and chop a song faster than any GUI.

Waveform & Playback Hotkeys

BPM Hotkeys

6. System Settings

Clicking this brings up a settings popup. Here you can change your default audio output, and default input and output folders (these three options will be saved next time you open Qie).

Export Options

The settings dialog also includes two export toggles:

• Export 8 bar MIDI loops — When enabled, Qie transcribes each stem segment into a standard MIDI file (see MIDI Generation below).
• Create Audio && MIDI ALS sessions — When enabled, Qie generates ready-to-open Ableton Live projects (see Ableton Project Generation below).

Both options are disabled by default and can be toggled on in Settings.

Additionally this is where you can read the manual and activate the license.

7. Playback Panel

You want to start by selecting a "B1" location for your song, as in where we are going to start counting. Usually this would be the first "one beat" of the kick that we hear, but I'm leaving that up to you.

Remember that your "B1" location is anchored and never moves, all BPM grid lines move in relation to the B1.

The moment you've selected your "B1", Qie's internal algorithm calculates up to 4 more locations to the right of the track locked to 8 bar markers. Allowing you to scan throughout your track from beginning to end using hotkeys 1 - 5.

8. Metronome & Volume

Toggle the Metronome on with hotkey M to hear a click track synced to your BPM grid. Use the volume slider to adjust the metronome level independently of the track playback.

You'll find that the GUI allows you to find the BPM much faster than a DAW because you can easily toggle the Metronome, cycle through the BPM Change Selector (hotkey: Shift + Left / Shift + Right), and adjust the BPM Value by micro amounts (hotkey: Shift + Up / Shift + Down) — all relative to where you set your B1.

9. Waveform Window

The waveform display shows your track's audio with the BPM grid overlaid. Use G to toggle the grid overlay, zoom in/out with Up Arrow / Down Arrow, and set your B1 marker with Shift + Click directly on the waveform.

10. Progress Bar

Songs run through Qie go through a multi stage process after you hit the Process Audio button (or press P). The progress bar shows the current stage.

11. Process Audio Button

Click this button (or press P) to begin processing your loaded track. Qie will separate stems, generate 8 bar loop segments, and optionally create MIDI files and Ableton projects based on your Settings.

Input & Output

Input Processing

Qie has two ways of processing a song:

1. Manually drag a song into the waveform GUI section
2. Place any song into an input folder (which you can change in Settings) before you open Qie

Default input folder locations:

• Mac: ~/Documents/Qie/Input
• PC: C:\Users\YourUserName\Documents\Qie\Input

Supported Audio Formats & Sample Rates

WAV, MP3, FLAC, M4A/AAC, and AIFF -- at any sample rate (e.g., 44.1kHz, 48kHz, 96kHz, 192kHz).

All input files are automatically converted to 44.1kHz WAV for processing and output of final stems and segments.

Output Folder Location

Qie saves the stems/segments to an output folder (which you can change in Settings).

• Mac (default location): ~/Documents/Qie/Output
• PC (default location): C:\Users\YourUserName\Documents\Qie\Output

Finding the Exact BPM Grid

This section covers how to quickly utilize Qie's waveform and playback controls to determine the BPM and export perfect 8 bar loops.

NOTE: You don't need to use the waveform GUI if you just want full stems, only if you want to create perfect 8 bar loops.

Final Output Files

Let's say we hit the Process Audio button with this B1 location:

Qie used your "B1" location along with your BPM Value to cut forwards and backwards in time to create 8 bar loops (labeled by BPM and Key). The output segments folder has a numbering system so your 8 bar segments are in order, from the beginning of your song to the end of your song.

Stem Types

Qie produces 10 stems from each song:

• Bass
• Vocals
• Melody
• Drums (full mix)
• Drums-Kick
• Drums-Snare
• Drums-Hh
• Drums-Cymbals
• Drums-Toms
• Drums-Ride

Segments Naming Convention

The general naming convention is:

TrackTitle | [BPM Key] | StemPart | Segment#[Bar#] | [Audio Density]

TrackTitle — Value in the track title field (1).

• Example: Artist-Song

[BPM Key] — Values in the BPM Value (2) and Key Value (4).

• Example: [127 BPM 9A E minor]

StemPart — Bass, Vocals, Melody, Drums (full), Drums-Kick, Drums-Snare, Drums-Hh, Drums-Cymbals, Drums-Toms, Drums-Ride

• Example: Bass

Segment#[Bar#] — The precise location of the segment within the song's timeline, structured for sorting.

• Segment#: A sequential number (S01, S02, etc.) that orders each 8-bar segment chronologically from the beginning of the song to the end.
• [Bar#]: The starting bar of the 8-bar segment, always represented by three digits.
• Segments are created in 8-bar increments; so the next segment starts at Bar009, then Bar017...
• For segments before Bar 1 (e.g., in a DJ intro), the bar number is negative. The letter N is used to denote "Negative". For example, the 8-bar segment starting at bar "-7" would be BarN07.
• Example: S02[Bar009] represents the second segment of the song, which starts at Bar 9.

[Audio Density] — A 9-block visual representation of the audio energy within that 8-bar segment, this helps you instantly gauge the loudness or intensity of a clip without having to listen to it.

Advanced Features

MIDI Generation

When Export 8 bar MIDI loops is enabled in Settings, Qie automatically transcribes each stem segment into a standard MIDI file after processing.

How MIDI Generation Works

• Melodic stems (Bass, Melody, Vocals) are transcribed using the basic-pitch AI model, which detects pitch, note timing, and velocity with customized frequency ranges per stem.
• Drum stems (Kick, Snare, Hi-Hat, Cymbals, Toms, Ride) use onset detection with intelligent classification — for example, hi-hats are classified as open or closed based on decay time analysis.

MIDI Output

• Location: 8 Bar Loops - MIDI/ subdirectory within your output folder
• Format: Standard .mid files, compatible with any DAW
• Naming: Follows the same convention as audio segments
• Each file contains a single instrument track spanning 8 bars (32 beats) at the detected BPM

Ableton Project Generation

When Create Audio && MIDI ALS sessions is enabled in Settings, Qie generates complete Ableton Live Set (.als) projects that can be opened directly in Ableton Live 12+.

What Gets Created

Two separate projects are generated:

1. Audio Ableton Project — Contains 10 color-coded audio tracks (one per stem) in Session View. Each 8-bar segment becomes a clip with warp enabled (Complex Pro mode), follow actions set to auto-advance, and key/scale metadata embedded.

2. MIDI Ableton Project — Contains MIDI tracks with transcribed note data from the MIDI generation stage. Includes scale information converted from Camelot notation.

Ableton Output

OutputFolder/
├── {TrackName} als-project - Audio/
│   └── {TrackName} - Audio.als
└── {TrackName} als-project - MIDI/
    └── {TrackName} - MIDI.als

CLI Automation

Qie supports command-line flags for automation and batch workflows:

Example:

bash
qie --process "/path/to/track.mp3" --output-dir "/Volumes/Drive/Output"

Rekordbox Integration

If you use Rekordbox to manage your music library, Qie can automatically pull BPM, Key, and downbeat position from Rekordbox's analysis data. No manual export required -- Qie reads directly from Rekordbox's database in real-time.

How Rekordbox Integration Works

When you load a track into Qie, it checks whether that file exists in your Rekordbox library. If found, Qie instantly uses Rekordbox's data instead of running its own BPM and key analysis. This is faster and lets you leverage the grid corrections and cue points you've already set in Rekordbox.

B1 Downbeat Priority

Qie determines the B1 marker position using this priority:

1. Hot Cue A -- If you've set Hot Cue A in Rekordbox, Qie uses it as the B1 position. This is the highest-confidence option because it reflects your intentional "start here" marker.
2. Beat Grid -- If no Hot Cue A is set, Qie reads the beat grid and uses the first downbeat (beat 1) position.
3. Manual -- If the track isn't in Rekordbox, B1 defaults to the start of the file and you can set it manually with Shift + Click.

What Gets Imported

Requirements

• Rekordbox must be installed on the same machine (free tier is sufficient)
• Tracks must be analyzed in Rekordbox (dragged into the Collection with analysis complete)
• Close Rekordbox before using Qie -- Qie reads the database in read-only mode, but Rekordbox holds a write lock while running
• If Rekordbox isn't installed or the track isn't in your library, Qie silently falls back to its own analysis -- no errors

Tips for DJs

• If Rekordbox's automatic beat grid is slightly off, correct it in Rekordbox first, then load the track in Qie -- Qie will use your corrected grid
• Setting Hot Cue A at the first musical downbeat in Rekordbox is the most reliable way to ensure Qie's B1 lands exactly where you want it
• This works with tracks stored anywhere -- external drives, Desktop folders, etc. -- as long as they've been imported into Rekordbox

Command-Line Usage

Everything Qie does in the GUI can also be done from the terminal. This is useful for processing large collections, tagging files, or building automation workflows.

Opening Terminal

If you've never used the terminal before:

• Mac: Open Spotlight (Cmd + Space), type Terminal, and press Enter
• PC: Open the Start menu, type Command Prompt or PowerShell, and press Enter

How to Run Qie from the Terminal

On Mac, apps are actually folders. The real program lives inside the app bundle at a specific path. On PC, you run the .exe directly.

Mac — full path (copy-paste this):

bash
/Applications/Qie.app/Contents/MacOS/Qie

PC — full path:

bash
"C:\Program Files\Qie\Qie.exe"

Tip: You can also drag Qie.app from your Applications folder into the Terminal window -- macOS will paste the full path for you. Then just add a space and your flags after it.

Every command below follows the same pattern: the path to Qie, then one or more flags. On Mac, all examples use the full /Applications/Qie.app/Contents/MacOS/Qie path. If you installed Qie somewhere else, adjust accordingly.

---

Batch Processing

Process an entire folder of songs through the full Qie pipeline (stem separation, drum separation, 8-bar segmentation, MIDI, and Ableton project generation) in one command. The GUI never opens -- everything runs in the terminal.

bash
# Mac -- process all audio files in a folder
/Applications/Qie.app/Contents/MacOS/Qie --batch "/path/to/songs"

# Mac -- with a custom output directory
/Applications/Qie.app/Contents/MacOS/Qie --batch "/path/to/songs" --batch-output "/path/to/output"

# PC
Qie.exe --batch "C:\path\to\songs"
Qie.exe --batch "C:\path\to\songs" --batch-output "C:\path\to\output"

Qie will scan the folder for all supported audio files (wav, mp3, flac, aiff, m4a), look up each track in your Rekordbox library for BPM/Key/B1 data, and fall back to audio analysis if Rekordbox doesn't have it. Songs are processed one at a time with memory cleanup between each.

Progress prints to the terminal as each song completes:

[BATCH] Starting: 12 files in /Users/you/Music/Set
[BATCH] [1/12] Processing: Track One.mp3
[BATCH] [1/12] Completed: Track One.mp3
[BATCH] [2/12] Processing: Track Two.flac
...
[BATCH] ===== COMPLETE =====
[BATCH] Completed: 11 | Failed: 0 | Skipped: 1 | Total: 12

MIDI generation and Ableton project generation follow your current Settings -- make sure to enable them in the Qie GUI Settings before running batch if you want those outputs.

Rekordbox + Batch Processing

If you've already gridded and analyzed your tracks in Rekordbox, batch processing is the most powerful way to use Qie. Rekordbox stores BPM, Key, beat grids, and Hot Cue positions for every track -- and Qie reads all of it automatically. That means zero manual input: no setting B1 markers, no correcting BPM, no selecting keys.

Point Qie at your entire DJ library (or an external drive) and walk away:

bash
# Mac -- process your whole Rekordbox library on an external drive
/Applications/Qie.app/Contents/MacOS/Qie --batch "/Volumes/DJ Drive/Music" --batch-output "/Volumes/DJ Drive/Qie Output"

# Mac -- process a specific genre folder
/Applications/Qie.app/Contents/MacOS/Qie --batch "/Volumes/DJ Drive/Music/House" --batch-output ~/Documents/Qie/House

# PC
Qie.exe --batch "D:\Music" --batch-output "D:\Qie Output"

For tracks where Rekordbox has BPM but no key, or tracks that aren't in Rekordbox at all, Qie falls back to its own audio analysis automatically. If you've set Hot Cue A in Rekordbox as the first musical downbeat, Qie will use that as the B1 marker -- giving you perfectly aligned 8-bar segments without any manual work.

BPM/Key Tagging

Analyze audio files and write BPM, Key, and Camelot notation directly into the file's metadata tags. These tags are compatible with Rekordbox, Traktor, Serato, and other DJ software.

bash
# Tag a single file
/Applications/Qie.app/Contents/MacOS/Qie --tag song.mp3

# Tag all audio files in a folder
/Applications/Qie.app/Contents/MacOS/Qie --tag /path/to/music

# Tag recursively (subfolders included)
/Applications/Qie.app/Contents/MacOS/Qie --tag /path/to/music --recursive

# Preview results without writing tags (dry run)
/Applications/Qie.app/Contents/MacOS/Qie --tag song.mp3 --dry-run

# Only tag BPM (skip key analysis)
/Applications/Qie.app/Contents/MacOS/Qie --tag song.mp3 --bpm-only

# Only tag Key (skip BPM analysis)
/Applications/Qie.app/Contents/MacOS/Qie --tag song.mp3 --key-only

# JSON output for scripting
/Applications/Qie.app/Contents/MacOS/Qie --tag song.mp3 --json

Example output:

Processing: /Users/you/Music/Track.mp3
  BPM: 128
  Key: A minor [8A] (confidence: 87.3%)
  Tags written.

Tags written per format:

Launch Qie from Terminal with Options

You can open the Qie GUI from the terminal with flags to preload a file, jump to a specific time, or auto-start processing -- useful if you want to skip the drag-and-drop step.

bash
# Open the GUI with a file already loaded (ready to play, no auto-processing)
/Applications/Qie.app/Contents/MacOS/Qie --load song.mp3

# Open with a file loaded and jump to 30 seconds in
/Applications/Qie.app/Contents/MacOS/Qie --load song.mp3 --seek 30

# Open the GUI and immediately start processing a file
/Applications/Qie.app/Contents/MacOS/Qie --process song.mp3

# Same as above, but save output to a specific folder
/Applications/Qie.app/Contents/MacOS/Qie --process song.mp3 --output-dir /path/to/output

All CLI Flags

Common

Advanced

Qie Creative Ideas

Qie is a unique piece of software in that it's not only the best stem separator for direct remixes but also creates highly organized loops built on music you love to inspire completely original music production. In many DAWs (like Ableton), you can cue/preview these loops in time with your new song.

Drum Example

Send a couple of tracks into Qie and start a new project at a new tempo, take the cymbal loop from a 160 BPM jungle track, the snare from a 90 BPM hip hop boom bap track, the kick from a 130BPM broken beat techno -- send each stem segment into a plugin fx, mangle it up, glue them all together and create a completely unique beat.

Melodic Example

Start a song in lets say C minor (5A), lets say you've got a chord progression already laid out. Search your loops library (filled with Qie loops from songs you love) for "5A" to find a bass line, a synth sequence (labeled "Melody"). I can even take something in F# Minor 11A and polyphonically retune it. Find a loop and convert it to MIDI just for the notes. Throw three melodic loops within circle of fifths of each other: 5A, 4A and 5B into a sampler, play middle C, apply a gate sequencer effect on it, mangle it and know you'll be in key. I mean the possibilities are endless.

Other Creative Uses

• Send vinyl recordings into Qie for 10 layers and load them into hardware samplers (MPC, Octatrack, Drum machines)
• Recover stems from old lost project files
• Use Case -- Your band records raw drum takes in a live room and you want an electronic producer to reinterpret it -- Qie has the best sounding drum separation model
• Study the arrangements of songs -- since Qie outputs 10 stems and 8 bar segments per stem, you can have a more detailed analysis
• Add harmonic / drum layers to live and DJ sets
• Rapid sample pack development: run your own songs through Qie, organize loops into folders by stem type, key, and BPM -- and build your own royalty-free loop packs for Splice, Bandcamp, or Gumroad
• Open the generated Ableton projects to remix directly in your DAW with all stems pre-loaded and warped

Thanks for taking the time to read this manual and supporting Qie.

Tell me how you're using it, what suggestions you have or any bugs you're experiencing.

Contact @ dian.nao.software@denniscao.net

Dennis Cao / 曹皓伟

Dian Nao [电脑] Software

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