Stemly
Complete guide — from first launch to live performance. Step by step.
Table of Contents
- Requirements & hardware
- First launch — selecting a folder
- Preparing your audio files
- App structure, tabs & modes
- Creating your first song
- USB channel routing
- Creating playlists & setlists
- Live playback — Song tab
- Live stereo mixer
- Song lyrics
- Out/Vol Presets
- Database backup — essential before every show
- Pre-show checklist
- Audio formats, conversion & track limits
- Bluetooth foot pedal
- Play Mode Settings — headphone mix
- CPU & RAM monitor
⚡ Quick Start — first 5 minutes
1 Requirements & hardware
| Item | Requirement |
|---|---|
| Device | iPad (recommended) or iPhone |
| System | iOS 17.6 or later |
| USB audio interface | Any USB-C interface with multi-out support (e.g. Behringer XR18, Allen & Heath, Roland) |
| Connection | USB-C cable directly from iPad to mixer or interface |
| USB hub (recommended) | Hub with PD input (Power Delivery — charges device during show) + USB-A port for audio interface or digital mixer. For older Apple devices: Apple Lightning OTG Camera Adapter. |
| Audio files | WAV, AIFF, MP3 — stereo or mono |
2 First launch — transferring audio files
On first launch Stemly automatically creates an Audio folder in your device’s Documents directory. You just need to copy your audio files there.
How to transfer files to iPad
- AirDrop — send files from Mac or iPhone directly to iPad. In the Files app, move them to On My iPad → Stemly → Audio.
- iCloud Drive — upload from Mac, download on iPad via Files app, then move to the Audio folder.
- USB cable + Finder (Mac) — connect iPad, open Finder → select iPad → Files tab → drag files into the Stemly folder.
- Dropbox / Google Drive — download files to iPad, then move to the Audio folder using Files app.
The folder Files → On My iPad → Stemly is the app’s own sandbox. When you uninstall Stemly, this entire folder is permanently deleted — along with every audio file, lyrics text and database backup stored inside it.
Recommended: Keep a backup copy of your audio files and database export in iCloud Drive or on your Mac.
3 Preparing your audio files
Each stem in a song is a separate audio file. Make sure your files are ready before importing.
Supported formats
| Format | Notes |
|---|---|
| WAV 48kHz / 24-bit | Best choice for live performance — recommended |
| WAV 44.1kHz / 16-bit | Works correctly, smaller file size |
| AIFF | Equivalent alternative to WAV |
| MP3 | Supported — smaller files, useful on storage-limited devices (e.g. iPhone 64 GB). Not recommended for professional live use due to lossy compression. |
File naming
File names can be anything — you assign them to a song manually inside the app. Keeping things organised helps, for example:
01_Kick.wav • 02_Bass.wav • 03_Keys.wav • 04_BackingVox.wav
4 App structure, tabs & modes
Stemly is organised into main work areas accessible from the tab bar at the bottom of the screen. The visible tabs depend on device and UI mode.
Project
Build songs here: add stems, set OUT routing, edit TrackName and Vol, save songs to the library.
Songs
Live playback area. Song library, Single / Queue workflow, PLAY and STOP, live mixer and queue.
PlayList
Build and reorder setlists. Available in Advanced mode and on iPad layouts.
Lyrics
Lyrics editor (TXT/RTF), QR sharing and wireless display on any device with a browser.
Settings
Audio folder, USB device config, database export/import, AutoLyrics and UI mode.
5 Creating your first song
A song is a collection of audio stems playing simultaneously. Each stem can be routed to a different USB output channel on your mixer.
- Open the Project tab.
- In the left panel (File Browser), tap an audio file — it is added automatically as a new stem.
- In the Channel Strip, set the USB output number (OUT) for each stem.
- Use TrackName to enter a short alias for the live mixer if needed.
- Set Vol per stem. For true stereo files and linked 2x mono pairs, edit Vol and TrackName only on the left channel — the right side follows automatically.
- Enter a title for the song and tap Save Song to save it to the global song library.
6 USB channel routing
This is the heart of Stemly — each stem goes to a separate USB output, which feeds its own channel on your mixer. Every stereo file is automatically split into a left channel (L) and a right channel (R) — each sent to its own USB output line.
Example routing for 4 stereo stems:
| Stem | USB output | Mixer channel |
|---|---|---|
| Drums | OUT 1+2 | CH 1–2 |
| Bass | OUT 3+4 | CH 3–4 |
| Keys | OUT 5+6 | CH 5–6 |
| Backing Vox | OUT 7+8 | CH 7–8 |
7 Creating playlists & setlists
A playlist is a collection of songs. You can have multiple playlists — one per tour, one per venue, one per set.
Adding songs to a playlist
- In the Songs tab, tap “Build Playlist” (orange button at the top of the song list). Checkboxes appear next to each song.
- Tap songs to select them — a checkbox appears next to each selected song.
- Tap “Add X to Playlist” to add the selected songs to an existing playlist or create a new one.
Reordering and deleting songs in a playlist (iPad)
- Open the PlayList tab (iPad only). In the left column, find the playlist you want to edit.
- Tap the pencil icon (✍) on the right side of the playlist row to enter Edit mode.
- Drag songs to reorder them, or swipe left to delete a song from the playlist.
- Tap “Done” to exit Edit mode.
8 Live playback — Song tab
This is where you work during a show. All your songs, full control.
- Tap a song name — it gets loaded and prepared for playback.
- On iPad you can choose Single or Queue above the mixer. Single works with one song at a time. Queue lets you prepare the next songs in order.
- Press PLAY (requires 2 taps) — playback starts immediately.
- Use the A–Z bar on the right to jump instantly to any song.
- Press STOP (requires 3 taps) to stop playback.
Song list indicators
| Indicator | Meaning |
|---|---|
| Green + play icon | Currently playing song |
| Queue number badge | Song position in the queue |
| Subtle blue highlight | Currently selected / loaded song |
| Orange highlight + “NEXT” label | Song queued from Stemly Remote (Android) — will load automatically after current song ends |
Single vs Queue mode (iPad)
Above the mixer on iPad you will find two mode buttons:
| Mode | Behaviour |
|---|---|
| Single | One song at a time. Selecting a new song immediately replaces the current one. |
| Queue | Songs are added to a numbered queue (up to 10). The next queued song loads automatically after the current one ends. |
Adding songs to a playlist from the Songs tab
On iPad, tap “Build Playlist” (button in the header bar) to enter selection mode. Checkboxes appear next to songs; after selecting them, tap “Add X” to assign them to an existing playlist or create a new one. On iPhone this shortcut is hidden to keep the live layout simple.
Audio monitoring — Audio Lost banner
Stemly monitors audio playback in real time. If sound stops unexpectedly — for example after the iPad goes to sleep, another audio app (like Spotify) was used in the background, or the USB audio interface briefly disconnected — a red “Audio Lost” banner appears at the top of the Songs tab.
- The Audio Lost banner appears automatically above the queue area — no action needed to detect the problem. The timer continues running normally.
- Tap Restart Stemly in the banner — Stemly rebuilds the audio engine and resumes playback without closing the app or restarting the song.
Stemly Remote — wireless remote control
Stemly Remote is a companion app for iPad/iPhone that acts as a wireless remote for Stemly. It connects via Wi-Fi (MultipeerConnectivity) — no internet required, just the same local network or hotspot. In Airplane Mode both devices communicate via Bluetooth.
Connecting
- Launch Stemly on the host device (the one connected to the mixer).
- Launch Stemly Remote on the remote device.
- Connection is automatic — a green dot in the top bar confirms it.
- Stemly Remote immediately downloads the full playlist and song library from the host.
Top bar
| Indicator | Meaning |
|---|---|
| 🟩 Green dot + “Connect to Stemly” | Connected to host |
| 🔴 Red dot + “Searching…” | Looking for host |
| ▶ NOW PLAYING | Host is currently playing |
| ■ STOP | Host is stopped |
View toggle — Song / Playlist
| View | What it shows |
|---|---|
| View Song (orange) | All songs from all playlists, sorted A–Z. Use the alphabet bar on the left to jump instantly. |
| View Playlist (green) | Playlist list → tap a playlist → its songs appear with the alphabet bar. |
Selecting a song
Tap any song in either view → it loads on the host (Stemly) and the lyrics appear automatically in the right column (yellow header = current song title).
The lyrics column also updates automatically when the host changes a song from its own screen, or when Stemly Remote just connected.
Queuing during playback
When the host is NOW PLAYING:
- Tapping a song queues it (yellow highlight) — it does not interrupt playback.
- The queued song is immediately sent to the host — it appears in the Stemly Songs list highlighted in orange with a “NEXT” label, identical to a queue from Android Remote.
- Tap the trash icon 🗑 next to a queued song to remove it from the queue.
- When the host stops → Stemly Remote automatically loads the queued song. Press PLAY twice to start.
PLAY / STOP confirmation
| Button | Taps required | Sequence |
|---|---|---|
| PLAY | 2 | PLAY → PLAY? → starts |
| STOP | 3 | STOP → STOP? → STOP?? → stops |
Auto-switch to Song view
When the host starts playing, Stemly Remote automatically switches to Song view after 2 seconds — regardless of which view was active or the Auto-Lyrics setting in Stemly.
Device combinations — iOS
| Host (Stemly) | Remote (Stemly Remote) |
|---|---|
| iPad | iPhone |
| iPhone | iPad |
| iPad | iPad |
| iPhone | iPhone |
One host supports one Stemly Remote at a time.
Stemly Remote Android
Stemly Remote is also available as an Android app (eu.bandistudio.stemlyremote.android). It connects to the Stemly host via Wi-Fi (local network or hotspot) and provides the same song browsing and queue control as the iOS version.
| Feature | Android Stemly Remote |
|---|---|
| Connection | Wi-Fi — same local network as the Stemly host (iPad/iPhone) |
| Song list | Full A–Z song library, alphabet bar for quick navigation |
| Queueing | Tap a song while host is playing → it appears highlighted orange with “NEXT” label in the iPad Songs list |
| Playlist view | Browse and select by playlist |
Best practices
- Set Auto-Lock → Never (Settings → Display & Brightness) on the Stemly Remote device — MultipeerConnectivity does not work when the screen is locked.
- Enable Background Audio on the host (Stemly) — playback continues even if the host screen turns off.
9 Live stereo mixer
The faders in the Song tab let you adjust volume for each stereo channel pair in real time — without stopping playback.
| Action | Result |
|---|---|
| Drag fader up | Increase volume for that channel pair |
| Drag fader down | Decrease volume |
| Number below fader | Current volume in percent |
| Red fader | Channel muted |
Splitting a stereo pair into mono channels
Each fader pair (e.g. 1+2, 3+4) has a 🔗 chain icon in its header:
| Icon state | Meaning |
|---|---|
| 🔗 grey | Channels linked (stereo) — one fader controls both |
| Tap grey icon | Pair splits into two independent mono faders |
| 🔗 orange | Channels unlinked (mono) — each has its own fader and level |
| Tap orange icon | Pair links back to stereo (volume averaged) |
Saving mixer volume settings
The mixer lets you save the current fader levels and link/unlink state directly with the song. After your soundcheck, tap SAVE (the orange banner that appears when you change anything) to store the mixer state as part of the song’s configuration.
- In the Songs tab (or PlayList tab), set the faders and stereo/mono state to the desired values for the current song.
- An orange SAVE banner appears automatically as soon as you move a fader or change a link/unlink state.
- Tap SAVE in the banner — the fader positions and channel link states are saved and will be automatically restored the next time you load this song in either tab.
Mixer sync between Songs tab and PlayList tab
Mixer settings are stored in a single shared snapshot per song. This means:
- Settings saved in the Songs tab are immediately visible when you select the same song in the PlayList tab — and vice versa.
- Both tabs have an identical orange SAVE banner — you can save from either place.
- The link/unlink state of each channel pair is saved together with the volume levels — no need to re-split channels after reloading.
- Last save wins — if you save in Songs and then save again in PlayList, the PlayList save overwrites the previous one.
Light header bar above the faders
The area showing the channel number and 🔗 icon has a slightly lighter rounded background. It serves two purposes:
- Visually suggests the fader row can be scrolled horizontally (there may be more faders than visible)
- Practically gives a safe area to swipe — touching a fader immediately changes volume, while swiping on the light header bar scrolls the view without accidentally moving any levels
Channel alias
Every fader can have a short label — an alias — displayed above the channel number during your show.
Setting an alias (PROJECT tab)
In the track edit view, between the filename and the S (Solo) button, a small text field appears with the placeholder NameTrack. Enter a short name, for example:
snr • kic • bas • voc • gt1 • key
- Maximum 8 characters
- Alias is saved with the song
- Leave it empty — the fader looks normal with no changes
Displaying the alias above the fader (SONG tab)
When an alias is set, it appears above the channel number in the fader header — in blue bold monospace font. Visible on both stereo faders (1+2) and mono faders (after unlinking a pair).
Fader header — fixed height
The grey header area has a fixed height regardless of whether an alias is set. This means:
- The volume fader always starts at the same position
- Switching stereo ↔ mono never shifts the fader
- The taller header gives a more comfortable surface for swiping horizontally — without risk of accidentally adjusting volume
10 Song lyrics
Stemly has a built-in Wi-Fi lyrics server. After pressing PLAY the app automatically switches to the Lyrics tab after 2 seconds (AutoLyrics).
Where to store lyrics files
Lyrics files are stored in the app’s built-in folder — always accessible, no folder selection needed after restart:
Files → On My iPad → Stemly → Lyrics
- Recommended format: TXT (UTF-8). RTF is also supported.
- File name must match the song title in the app (case-insensitive, tolerant of special characters).
- Green ✓ icon next to a song = lyrics file found. Red ! icon = file missing.
- Long-press a song title in the right-hand list → opens the lyrics file manager for that song.
- Place your TXT lyrics files in Files → On My iPad → Stemly → Lyrics.
- Make sure the host device is connected to the same local network as the receiving device.
- Open the Lyrics tab and use the QR button to share the lyrics page quickly.
- The current song’s lyrics appear automatically and change with your song selection or setlist flow.
Network options for lyrics display
| Receiving devices | Network needed | Recommendation |
|---|---|---|
| iOS only | No extra router needed | All Apple devices connect directly — works in Airplane Mode via Bluetooth / Wi-Fi Direct. Turn on Personal Hotspot on the host if needed. |
| Android, Windows, other OS | Shared local Wi-Fi required | All devices must be on the same network. Best: bring your own portable router. Do not rely on venue Wi-Fi. |
Recommended: Set Settings → Display & Brightness → Auto-Lock → Never before going on stage.
If the screen did turn off: Wake the host device, then refresh the browser on Android / Windows / Mac — lyrics synchronisation resumes immediately.
How to fix: Make sure the song title (as entered in Project) and the lyrics file name on disk are identical.
Lyrics tab header — host display
While a song is playing the Lyrics tab header shows three elements side-by-side:
| Element | What it shows |
|---|---|
| Song title | Current song — white text |
| -3:42 countdown | Time remaining in the current song — green monospaced, updates every second |
| Next: [title] | Next queued song title — orange text, 17 pt. Appears only when a song is queued from either Remote (iOS or Android). |
Now Playing & Next Song — Wi-Fi broadcast
Stemly now broadcasts live song information to all connected receivers over Wi-Fi. The browser page on every receiving device updates in real time — no refresh needed.
| Broadcast data | Description |
|---|---|
| Now Playing | Title of the currently playing song — displayed prominently on all receivers |
| Next Song | Title of the song the user has queued — shown as a subtitle below the current title on all receivers |
Countdown timer
Stemly shows a live countdown to the end of the current song in two places:
| Location | What you see |
|---|---|
| Lyrics tab (host) | A green -3:42 timer appears in the header next to the song title, updating every second. Disappears when playback stops. |
| Wi-Fi receivers (browser) | The same countdown is broadcast via SSE and displayed at the top of the browser page. Resets to blank when playback stops. |
11 Out/Vol Presets
A preset saves your entire output channel and volume configuration — load it with one tap into any new song.
How to save an Out/Vol Preset:
- In the Project tab, set the output channels and volumes for all stems.
- Tap Out/Vol Presets → Save Setting.
- Enter a name, e.g. “Standard 4 stereo”, and tap Save.
How to load a preset into a new song:
- Add stems to the new song.
- Tap Out/Vol Presets → Load Setting and select from the list.
- Output channels and volumes are applied automatically — done.
12 Database backup — essential before every show
The Stemly database holds all your playlists, songs, and routing. It’s one JSON file — protect it.
How to back up:
- Go to the Settings tab.
- Tap Export Database.
- Choose where to save: iCloud Drive, AirDrop to Mac, or send by email.
How to restore:
- Go to Settings → Import Database.
- Select your JSON backup file.
- All playlists and songs are restored immediately.
13 Pre-show checklist
Before every performance, verify:
- Database backed up (Settings → Export Database)
- All audio files are in the local iPad folder — no missing stems
- Audio routing tested on the USB device during soundcheck
- PLAY/STOP tap count checked in Settings
- Lyrics server started and verified on at least one receiving device
- Auto-lock disabled: iOS Settings → Display & Brightness → Auto-Lock → Never
- iPad charged or connected to power via USB hub
14 Audio formats, conversion & track limits
What happens when you play different formats
| Format | What happens | Live show |
|---|---|---|
| WAV 48kHz | Loaded to RAM — zero processing during playback | ✅ Ideal |
| WAV 44.1kHz (converted) | Converted once at import, then loaded to RAM | ✅ Safe |
| WAV 44.1kHz (no conversion) | Plays ~2.4% faster — 4 min song ends 5–6 sec early, tracks desync | ⚠️ Home only |
| MP3 (converted to WAV) | Decoded once at import, stored as WAV 48kHz | ✅ Safe |
| MP3 (no conversion) | Real-time decoding on CPU — risk of glitches with many tracks | ❌ Avoid |
RAM usage — how much memory per track
| Format | 1 min mono | 1 min stereo |
|---|---|---|
| WAV 48kHz Float32 | ~11 MB | ~23 MB |
| MP3 / 44.1kHz (after conversion) | ~11 MB | ~23 MB |
Track limits by device (iOS 17.6)
| Device | RAM | Max tracks* |
|---|---|---|
| iPhone XR · iPad 7th gen · mini 5 | 3 GB | 5–6 tracks |
| iPhone XS · iPad Air 3rd gen | 4 GB | 8–10 tracks |
| iPhone 12 Pro · iPad Air 4th gen | 6 GB | 15 tracks |
| iPhone 14 Pro · iPad Air M1 | 6 GB | 15 tracks |
| iPhone 15 Pro · iPad Pro M2/M4 | 8–16 GB | 32 tracks ✓ |
* Values for 4-minute mono WAV 48kHz tracks. Stereo tracks use 2× the RAM.
Typical live show examples
| Setup | RAM used | Works on |
|---|---|---|
| 6 mono tracks · 4 min | ~264 MB | All devices |
| 8 tracks (4 mono + 2 stereo) · 4 min | ~268 MB | All devices |
| 12 tracks (8 mono + 2 stereo) · 4 min | ~444 MB | iPad Air+ |
| 20 mono tracks · 5 min | ~1100 MB | iPad Pro M2/M4 |
15 Bluetooth foot pedal
Stemly supports any Bluetooth foot pedal that pairs as a standard BT keyboard — for example the Joyo JSP-1 or any page-turner pedal used for PDF sheet music. No special drivers or CoreBluetooth setup needed.
How it works
BT pedals pair with iOS just like a Bluetooth keyboard. Once paired, Stemly captures the key events and maps them to stage actions: PLAY and STOP.
Pairing
- Put the pedal in pairing mode (usually hold the button until the LED flashes).
- On iPad/iPhone: Settings → Bluetooth → select the pedal from the list.
- The pedal is now paired. No action needed inside Stemly — just open the app.
Configuration in Stemly
Tap the pedal icon (🦶) in the Songs tab toolbar to open the Foot Pedal Settings panel.
| Action | What it does |
|---|---|
| PLAY | Triggers the PLAY button (with click-count safety) |
| STOP | Triggers the STOP button (with click-count safety) |
Assigning a pedal button to an action
- In the Foot Pedal Settings panel, find the action row (e.g. PLAY).
- Tap SET — the row highlights orange and the status bar shows “Press a key…”
- Press the pedal button you want to assign. The key name appears immediately.
- Press Escape (or tap Cancel) at any time to abort without saving.
Click mode — PLAY and STOP
PLAY and STOP each have an independent click mode selector:
| Mode | Behaviour |
|---|---|
| 1 click | Single pedal press triggers the action immediately |
| 2 clicks | Two presses within 0.8 s required — matches the on-screen PLAY/STOP safety tap count. Default. |
Key indicators
While waiting for a second click (2-click mode), a ? appears next to the PLAY or STOP label. If no second press arrives within 0.8 s, the counter resets automatically.
Clearing assignments
- Tap the ✕ icon next to an assigned key to clear that slot.
- Tap Clear all assignments at the bottom of the panel to reset everything.
Supported pedal models
Any BT pedal that pairs as a standard HID keyboard works. Confirmed examples:
| Pedal | Typical key sent |
|---|---|
| Joyo JSP-1 (left) | ← Left Arrow |
| Joyo JSP-1 (right) | → Right Arrow |
| Most PDF page-turner pedals | Page Up / Page Down or arrow keys |
16 Play Mode Settings — headphone mix
Play Mode Settings lets you mix the multitrack output to the iPad’s headphone jack — useful for personal monitoring, rehearsal, or whenever you are not connected to a USB audio interface.
Auto-Pan
When enabled, Stemly automatically distributes tracks across the stereo field. Each track receives a pan position derived from its assigned USB output channel, so the headphone mix stays balanced without manual adjustment.
| Track OUT assignment | Auto-Pan position |
|---|---|
| OUT 1 (L) / 2 (R) | Hard Left / Hard Right |
| OUT 3 (L) / 4 (R) | Centre-left / Centre-right |
| OUT 5 and above | Distributed evenly across stereo field |
Auto-Gain
Stemly counts the total number of active tracks and automatically calculates a gain reduction to prevent clipping in the headphone mix. As you add more tracks, the gain is reduced proportionally — so the combined signal never overloads the output.
| Active tracks | Auto-Gain reduction (approx.) |
|---|---|
| 2 | −3 dB |
| 4 | −6 dB |
| 8 | −9 dB |
| 16 | −12 dB |
17 CPU & RAM monitor
Stemly displays real-time CPU and RAM usage indicators in both the Project tab and the Songs tab, so you can keep an eye on device load at all times.
| Indicator | Location | What it shows |
|---|---|---|
| CPU % | Project & Songs | Current processor load — useful for spotting real-time MP3 decoding or heavy multi-track loads |
| RAM MB | Project & Songs | Memory used by the app — helps you stay within safe limits for your device (see section 14) |