What is Session™ Key?
Session™ Key is a macOS menu bar app that reads the musical key and the tempo of whatever is playing through the Mac's own audio output, then writes both into the open DAW project with one keystroke. It costs $49 once, with no subscription. It runs on Apple Silicon Macs on macOS 14.4 or later and on nothing else, and there is no Windows build.
Session™ Key is published by Capiscana, Inc., which operates this site. The DAWs named below are the products of their own companies, none of which has any involvement in this page. Every fact here is dated to the day the source was read.
The short version
- What it is
- A menu bar app for macOS. Not a plugin, not a web page, not a subscription. It sits at the top of the screen and reads what the Mac is playing.
- What it reads
- The Mac's own audio output. A track on the timeline, a streaming reference, a voice memo, a video in a browser tab: if the machine is playing it, the key and the tempo can be read.
- What it does with the answer
- One keystroke writes the tempo and the key into the open project in Pro Tools, Logic Pro, Ableton Live and Studio One. FL Studio receives the tempo only.
- Where it stops
- macOS 14.4 or later on Apple Silicon, and nothing else. Something has to be sounding for there to be a reading, and on material with no stable tonal center the reading is marked unsure.
What it does in a session
The two questions that open a session are the key and the tempo. Detectors that answer them have existed for years, and what they hand back is a number that somebody then types into the project by hand. Session™ Key reads the same two values and closes that second step: when a reading locks, one keystroke sends it into the DAW that is open, and the send is confirmed when it lands.
The source is the Mac's audio output rather than any one application. Nothing is routed, imported, or dragged anywhere. Whatever is audible on the machine is what gets read, which is why a reference playing in a browser tab is treated the same way as a bounce playing on the timeline.
A whole file can be read instead of a live stream. Dropping the finished file on the menu bar icon analyzes the track in one pass rather than following it as it plays.
How sure it says it is
Every reading carries a confidence mark. Green is a lock and the app stops listening by itself so the reading holds. Amber is an unsure reading, and an unsure reading names its contenders instead of picking one and presenting it as settled.
On drums, speech, noise, or anything else without a stable tonal center, a live reading stays amber. Tempo has a second ambiguity of its own: a groove that is equally defensible at half or double time can be flipped between the two, and the flip changes what is displayed and what gets sent, never the detection.
No accuracy percentage is published for Session™ Key, and none appears anywhere on this site. The confidence mark is what stands in place of one, and it can be checked in a few seconds on music the reader already knows.
What happens to the audio
Detection runs on the device. Audio is not uploaded, not recorded, and not stored in the cloud. The network is used for licensing and for checking for updates, and for nothing else. That distinction is the one that matters when the thing playing is an unreleased record.
What it writes into each DAW
Where it stops
- Platform. macOS 14.4 or later, Apple Silicon. There is no Windows build and no Intel build, and none is announced.
- FL Studio gets tempo and nothing else. The program has no project key field, so the key has no destination there. Every other supported DAW receives both.
- Something has to be playing. The source is the Mac's audio output. A file sitting on the timeline unplayed is not read, and a file has to be dropped on the icon to be analyzed on its own.
- Material with no tonal center reads as unsure. Drums, speech and noise hold at amber on a live reading. The mark is the answer in that case, not the letters.
- No accuracy figure is published for Session™ Key, and none appears on this site.
- It is not sold on its own yet. The product page said "launching soon" when it was read on 5 August 2026. A license is included with the Session Cards™ deck.
What it costs and what it runs on
Common questions
What does Session™ Key actually do?
It reads the musical key and the tempo of whatever is playing through the Mac's audio output, shows both in the menu bar with a confidence mark, and writes both into the open DAW project with one keystroke. Pro Tools, Logic Pro, Ableton Live and Studio One receive the key and the tempo; FL Studio receives the tempo only.
Is Session™ Key a plugin?
No. It is a menu bar app, not a VST, AU or AAX plugin. Nothing is inserted on a track and there is no bus, aux or hardware loop to configure, because the app reads the machine's audio output rather than a signal inside the session.
Does the audio ever leave the Mac?
No. Key and tempo detection runs entirely on the device, from the Mac's own audio output. Nothing is uploaded, recorded or stored in the cloud, and the network is used only for licensing and update checks.
What does it run on?
macOS 14.4 or later, on Apple Silicon. There is no Windows build and no Intel build. A Mac older than that requirement cannot run it.
How much does it cost?
$49 once, with no subscription. One license covers up to three Macs and carries a 30-day money-back guarantee. A license is also included with the Session Cards™ deck.
Sources
- Session™ Key manual, session.am/manuals/session-key. Read 5 August 2026 for the DAW send behavior, the confidence marks, the half and double time flip, and the on-device detection claim.
- Session™ Key product page, session.am/session-key. Read 5 August 2026 for price, license terms, system requirements and the "launching soon" status.