Key+ for iPhone.

Key+ is a handy tool for estimating the musical key of digital recordings and live audio. A must-have for musicians and DJ's, Key+ analyzes audio and returns both the key and it's relative major or minor signature.

Whether you're a musician looking to jam along in harmony with your favorite song, or searching for the perfect fit in your set, Key+ is here for you.

Download on the App Store

Live Audio. On the go.

This isn't a tuner. No more guessing at a key based on individual notes. Key+ listens to a full section of music and does all the dirty work for you. Whether there's a live orchestra in the room or it's pumping through your speakers, you'll be in the know.

Music Library. For your collection.

Unlock your favorite songs and join in. Select any track from your music library and add it to your repertoire. No need to find the key with a keyboard anymore, we'll do if for you.

Frequently asked questions.

Whats a relative key?

Relative keys are the major or minor scale of the same key signature. The relative minor of a major key, or the relative major of a minor key, is the key which has the same key signature but is based on a different root note. Transitions between songs that share relative keys will be smooth and painless.

Key+ gave me the wrong key. What gives?

Unfortunately, there's no key detection tool that is right 100% of the time. There are a variety of reasons why you might get the wrong result. Too much noise, too short of a sample, music with key changes, and of course, untuned instruments or detuned recordings. All we can do is estimate the key, and it usually works pretty well. As always, trust your ears above everything else.

Can Key+ write the key to the track's comments?

Unfortunately, Apple doesn't allow third-party apps to write data to any item within the music library.


Hows everything working out? Good or bad, drop us a line, we want to hear from you! [email protected]

Privacy Policy.

We don’t store your data, period.