Charcoal Player 사용 가이드

What Charcoal Player is

Charcoal Player is a practice-oriented music player for the Mac. It plays your audio files like any other player, but its feature set is aimed at people who are learning something by ear: musicians working out a part, singers rehearsing, and language learners who replay lectures or dictation passages. You can slow a track down without changing its pitch, loop one difficult phrase with precise boundaries, and split a song into separate parts so you can mute the one you want to play yourself. It is a macOS-only app distributed through the Mac App Store and requires macOS 15 or later.

Screens at a glance

The six screens follow the order of this guide: library, speed and loop, sound separation, speaker separation and export.

Main features

• Pitch-preserving speed control: play anywhere from 0.5x to 3.0x without the chipmunk or monster effect, which is what you want when transcribing fast passages.
• Sample-accurate A-B loop: set a start and end point and the loop repeats without drifting at the boundary. There are keyboard shortcuts for setting A, setting B, and toggling the loop.
• Sound separation (stems): the default mode splits a song into four parts (vocals, drums, bass, and other instruments). A six-stem mode additionally separates guitar and piano. The guitar and piano stems are labelled experimental, so quality varies from song to song.
• Custom skip interval: jump forward or back by an amount you choose, from half a second to thirty seconds.
• Library and playlists: add your practice folder once and the library persists across restarts and updates. You can also open files from Finder or drag them onto the window.
• Lyrics: show lyrics from .lrc or .txt files or from lyrics embedded in the file, with an adjustable offset.

The app has no ads, requires no account, and collects no usage data. Playback, speed control, A-B looping, and sound separation are free. Exporting separated audio to a file is free only a limited number of times per 24 hours; beyond that you unlock it with an optional in-app subscription (or a lifetime purchase). Prices can change, so check the store page for current details.

Getting started in five minutes

1. Install the app from the Mac App Store and open it.
2. Add the folder that holds your practice music, or simply drag a file onto the window to start playing. When you add a folder, the app remembers its access permission, so your list is still there next time.
3. Choose a track, press play, and use the speed control. Starting at around 0.7x to 0.8x and working upward is a sensible default.
4. Set A at the beginning of the phrase you are practicing and B at its end, then turn the loop on.

Using sound separation

Separation runs the whole song through a neural-network model and produces one audio track per part. You can start it from the track view with the separation button, and the result is cached so reopening the same song does not require another wait.

The model is downloaded once

The separation model is not bundled inside the app. The first time you use the feature, the app asks for your consent and then downloads it. That is the only time the feature needs the internet; afterwards the processing happens on your Mac, and your music files are not uploaded anywhere.

Turning parts on and off

When separation finishes you see one lane per part. Each lane can be muted or soloed. A drummer can mute the drums and play along, and a singer can solo the vocal line to study pitch and pronunciation. The workflows are described in more detail in How to practice an instrument with stem separation.

Practice tips

• Keep loops short: a long A-B region makes it hard to find the exact spot where you stumble. One to four bars works well.
• Raise speed in small steps: only speed up after you can play the loop cleanly several times in a row, and keep each increase modest.
• Expect to retune per song: the right speed and pitch setting differs between songs, so adjust again for each one.
• Solo a part to transcribe it: to learn a bass line, listen to the bass stem alone and slow it down if needed.

Common problems and fixes

• Traces of other instruments in a stem: this is a general limitation of AI separation, most noticeable with reverberant vocals or songs where several instruments share the same frequency range. Treat the result as a practice reference, not a studio-grade isolation.
• A folder shows as offline: this happens when an external drive is unplugged or a permission needs re-confirming. Tracks are not deleted; reconnect the drive or re-select the folder to restore them.
• Separation takes a long time: it depends on the song length and the Mac you use. Songs are processed one at a time, so for long tracks it is best to keep working on something else while you wait.
• Disk usage grows: separation results accumulate in a cache. Use the cache cleanup option in the settings to remove results you no longer need.

Privacy and copyright

The store listing states that Charcoal Player has no ads, no accounts, and no data collection. The network is used for downloading the separation model and for processing in-app subscriptions and purchases. See the privacy policy for details. The separation feature is meant for personal practice with music you own or are licensed to use. Sharing or distributing separated audio is a different matter and may require permission from the rights holder. This is general information, not legal advice.

Limits and known issues

• Mac only. It needs macOS 15 or later and there are no Windows or iPhone versions.
• Only export is rate-limited. Saving separated results as files is free up to 3 times per 24 hours; beyond that you need the optional in-app subscription (or lifetime purchase). Playback, speed change, A-B loop and the separation itself are free.
• A model is downloaded on first use. The separation model is not bundled; it is downloaded after you consent, and that is the only time internet is needed. Afterwards processing happens on your Mac and music files are not uploaded.
• Separation is not perfect. Tracks with heavy reverb or instruments in the same range bleed a little. Guitar and piano separation is classed as experimental, and as the screenshot shows some parts read "Not detected" depending on the track.
• Separation takes time depending on track length and Mac specs. One track is processed at a time, and results pile up in a cache that can grow disk use; you can clear it in settings.
• Copyright is your responsibility. It assumes personal practice with music you own or may use; publishing or distributing separated audio may need the rights holder's permission.

How it compares

The practice workflow itself is covered in more detail in how to practice with stem separation.

Frequently asked questions