The Idea
Transcription is how musicians have always learned. You put the needle back, again and again, until the phrase gives itself up. What you win that way you keep, because your ear did the taking — nobody handed it to you.
Software has spent twenty years trying to hand it to you. Point a piece of music at a machine and it prints the notes. It feels like help. It is the opposite of practice: the one difficulty worth having is the one that gets removed.
SLoop takes the other road. It makes the music slow enough to hear and the phrase short enough to hold — and then it gets out of the way. It does show you the pitches it thinks it heard, drawn on a real staff. Treat that as a second opinion from a colleague who is often right and sometimes wrong. You are still the one transcribing.
Slow, In Tune, and Seamless
Play any audio file from 25% to 200% speed with the pitch fully preserved. A passage at quarter speed stays in its original key, so what you learn slowly is exactly what you will play up to tempo. Transpose by semitones when the horn part sits in the wrong key for your instrument, or nudge by cents when the record itself was cut sharp.
Drag on the waveform to set an A–B loop, then pull the edge handles until it sits exactly on the phrase. The loop is gapless — audio is scheduled ahead of the seam rather than seeking back to it, so the return to A is a musical downbeat, not a stutter. Zoom and pan to work at the level of a chorus, a bar, or a single grace note.
Everything is a keyboard away: Space to play, A and B to plant the loop, ⌥↑ and ⌥↓ for volume, the arrows to nudge. SLoop remembers the file, the loop, the speed, and the markers between sessions — you come back tomorrow exactly where the phrase defeated you.
How It Works
Open a Recording
Drop in any audio file your Mac can read. SLoop draws the waveform and remembers the file next time you launch.
Set the Loop
Drag across the waveform, or press A and B as it plays. Drag the edge handles to tighten. Zoom in until the phrase fills the window and the boundaries stop being a guess.
Slow It Until You Can Hear It
Take it to 50%, or 25%. The pitch does not move. Loop it there until the notes separate from one another — then walk the speed back up.
Let the Trainer Push You
Trainer mode raises the speed by an increment you choose each time the loop comes round. Start where it's easy, arrive at tempo without ever noticing the step that would have broken you.
Check Your Ear Against the Staff
Press Detect. SLoop analyses the loop and engraves the pitches it heard on a grand staff, with 8va brackets when the line runs to the edges. Turn on note names if you want them spelled. Compare it to what you wrote down — and trust yourself when you disagree.
Mark the Music, Then Take It With You
Tap Measure on each downbeat as it plays and pick the meter. SLoop computes the tempo from your own taps, and the MIDI export lands every note on that grid — a quantized sketch you can open in Dorico, Logic, or Ableton and finish by hand.
What the Detection Is, and Isn't
SLoop's note detection is a helper, not a notation system. It listens for the strongest pitches in the loop and draws them. On a clean solo line it is often close to right. On a Hammond organ, a distorted guitar, or anything thick with harmonics, it will hear notes that were never played — an overtone is a real frequency, and the machine has no way to know you didn't mean it.
Two things help. Single mode tells SLoop the source is one voice, so it stops reaching upward for a melody hiding inside a mix. And a tighter loop is a better question: detection over four bars of a rich chord voicing will always be noisier than detection over one phrase of a single line.
We would rather say this plainly than let you discover it and conclude the app is broken. It is doing what it says. Transcription remains an ear skill — the staff is scaffolding, not an answer.
Key Features
Pitch-Preserved Speed, 25–200%
Slow a passage to a quarter of its tempo and it stays in the original key. Speed it past the record and it still does. The speed control tints as you move it — cool when you're under tempo, warm when you're over.
Gapless A–B Loop
Audio for the next pass is scheduled before the current one ends, so the loop point is seamless. Drag on the waveform to set it, then refine with edge handles until it lands on the beat.
Transpose & Fine-Tune
Shift by semitones to bring a part into your instrument's key. Nudge by cents when the recording sits between the frets — old records often do.
Real Bravura Notation
Detected pitches are engraved on a grand staff with Bravura — the SMuFL reference font used by professional engraving software — including 8va and 8vb brackets for extreme registers.
Single-Voice Detection Mode
Tell SLoop the source is one instrument and it stops biasing toward the upper voice. On a solo horn, guitar, or organ line, this is the difference between a readable staff and a cloud of overtones.
Note Names on Demand
Show the spelled name under every detected note when you want it, hide it when you'd rather read the staff. Off by default — reading is the point.
Trainer Mode
Each time the loop repeats, the speed climbs by an increment you set. Begin at 50%, end at tempo, and never meet the wall in between.
Markers & Computed Tempo
Place Beat, Measure, and Section markers as you listen. SLoop derives the tempo from your own taps rather than guessing at it — your sense of the pulse, not an algorithm's.
Quantized MIDI Export
Tap Measure on each downbeat, choose the meter, and the export lands every note on that grid, with the time signature written into the file. Open it in Dorico, Logic, Ableton, or any DAW and finish the transcription by hand.
Saved Loops
Keep the four bars you're working on. Come back to them tomorrow, or next month, without hunting for the spot again.
Session Memory
File, loop, speed, markers, zoom — all of it survives a quit. SLoop reopens where you stopped, which is usually mid-struggle.
Keyboard-First
Space plays. A and B plant the loop. ⌥↑ and ⌥↓ take the volume; click the speaker to mute. Your hands stay on the instrument, mostly.
Who It's For
Anyone Transcribing a Solo
The classic use. Slow it, loop it, write it down. The difference between a bebop line at 100% and at 40% is the difference between noise and notes.
Students Learning by Ear
Ear training that uses real music instead of exercises. Guess first, then look at the staff — the guessing is where the learning happens.
Teachers Preparing Material
Pull a phrase out of a recording, mark the bars, export a MIDI sketch, and finish the engraving in your notation program. A lesson handout in one sitting.
Players Working a Hard Passage
Not transcribing — just practising. Loop the two bars you keep dropping, and let Trainer mode walk you up to tempo one increment at a time.
Free to Try — Unlock When It's Yours
SLoop is free to download from the Mac App Store, and the whole app works from the first minute. A one-time unlock lifts the daily limit — no subscription, no account, nothing to sign up for.
SLoop — Free
- The entire app — nothing hidden, nothing degraded
- Pitch-preserved speed, gapless loop, zoom, transpose, trainer
- Note detection on a real Bravura grand staff
- Markers, computed tempo, quantized MIDI export, saved loops
- 5 minutes of playback per day. Reading the staff, setting loops, and navigating are always free — only further playback waits for tomorrow
SLoop Unlimited
- Lifts the daily limit — unlimited playback, forever
- One purchase, restored on all your Macs
- No subscription, no account, no analytics
Want to load from a link? The SLoop Full Edition, sold directly by us for $29.99, adds loading from an online link you already have access to — video and audio, so you can watch the technique. Everything else is identical.
No third-party SDKs, no tracking. Your files never leave your Mac.
Built by One Developer
SLoop is built by Çağlayan Yıldız at Puja Music Productions in Antalya, Turkey — alongside AllGoRhythmics (rhythm notation), MathRonome (polyrhythmic metronome), String Logic (theory for string instruments), Elvin's Numbers (children's number learning), and Aquadrum Pro (tongue drum companion).
It began as a tool he built for himself, because the transcription apps he tried kept offering to do the listening for him. It stayed a practice tool. No ads, no tracking, no data collection of any kind.
Frequently Asked Questions
No, and that's deliberate. It detects pitches and draws them on a staff as a second opinion. On a clean single line it's often close; on harmonically rich material it will show notes that were never played. Use it to check your ear, not to replace it.
No. Speed and pitch are independent. A passage at 25% stays in the original key. You can also transpose deliberately, by semitones or by cents, without touching the speed.
Yes. SLoop schedules the next pass of audio before the current one finishes, rather than seeking back to point A. The seam is inaudible, which matters when you're looping a two-bar phrase two hundred times.
By default the detector leans slightly upward, to pull a solo out of a full mix. If your source is a single instrument, that bias makes it chase overtones. Single mode switches the bias off — on a solo organ or horn line it cleans the staff up considerably.
Yes. Tap Measure on each downbeat as it plays and choose the time signature; the MIDI export then quantizes every note to that grid and writes the meter into the file. It arrives as a clean sketch to finish by hand, not a finished score.
One thing only. The Mac App Store edition works with audio files on your Mac. The Full Edition, sold directly by us, can additionally load audio from an online link you have access to. Everything else — the loop, the speed, the detection, the markers, the memory — is identical.
No. One purchase, and it's yours. No account, no login, no monthly anything.
No. No signup, no analytics, no third-party SDKs, no advertising. Your audio files are read from your own disk and never leave it.
Email support@pujamusic.com — we read everything and respond personally.