Groovelock: Key & BPM · iOS app
Groovelock listens to the music around you and shows its musical key and tempo on the Groove Wheel, an alphanumeric circle of fifths — live, on your phone, without recording anything. Readings are estimates from what the microphone hears: give a track 30 seconds, and use Analyze a File when you need an exact answer.
Key needs melody. During a drum-only intro, a breakdown or a build there is nothing to read, and Groovelock waits rather than guess. Let the track play into a section with chords or a bass line, keep the phone within a few metres of a speaker, and give it 30 seconds. If a track still won't lock, it is usually two-chord music that fits several keys: tap LOCK again on a different part of the track, or use Analyze a File for the whole track.
Two things to check. First, look at the Groove Wheel: if the two keys are next to each other, or the same number with a different letter, they are relative or neighbouring keys. They share almost all their notes, mix cleanly together, and DJ software itself disagrees on them — in our own library check two major analysers gave different answers on one track in four. Second, a 40-second listen through a microphone hears one section; your software analysed the whole file. Analyze a File in Groovelock does the same and will usually match.
Rare, but possible when the section has a strong vocal or lead line that pulls away from the underlying key. Tap the key on the wheel to release it and let Groovelock re-listen on the next section, or use Analyze a File.
Tap the TEMPO pill to set the range your music lives in, for example 100–200. Readings are folded into that range, so half-time and double-time readings resolve to the tempo you expect. The default is 100–200.
A microphone reading is accurate to a few tenths and keeps settling for the first half minute of a steady beat, so give it a moment. Prefer whole numbers? Settings → Tempo display. Analyze a File reports to 0.1 BPM from the full track.
Tempo needs a beat. In LOCK mode Groovelock holds its last confirmed tempo through a breakdown; in LIVE mode it waits for the beat to return.
Triplet-feel and 6/8 tracks can be heard at one and a half times their tempo. Set a tighter tempo range, or use Analyze a File.
Tap the TAP TEMPO pill, then tap the centre of the wheel on the beat. Four taps give a reading; keep tapping to refine it. Tap BACK TO WHEEL to return.
Open Settings → Privacy & Security → Microphone and switch on Groovelock, then tap LOCK again. The app opens the microphone only while LOCK or LIVE is running, and audio never leaves your phone.
Check the phone is not muted, the microphone is not covered by a hand or case, and the music is playing at a normal listening level from speakers. Music on headphones cannot be heard by the phone.
Very loud, very reverberant rooms are the hardest case. Move closer to a speaker, hold the phone still, avoid pointing it at the crowd, and give it a full 30 seconds. The booth monitor is usually a better source than the dance floor.
A phone call, Siri, plugging in headphones or switching apps stops the microphone. The screen says “paused — tap LOCK or LIVE to resume”. Tap either button to continue.
Any audio or video the phone can play: MP3, M4A, WAV, AIFF, FLAC, MP4 and MOV, including videos from the camera roll. Files up to 20 minutes. Pick Files for music and Photo Library for videos; the Photo Library shows videos only because photos have no sound.
The clip has no sound, or is over 20 minutes. Trim it, or choose another.
Copying a long video out of Photos can take a few seconds; the button reads “opening file…” while that happens, then “analyzing” with a percentage. A seven-minute track takes a few seconds on a recent iPhone.
Groove Wheel codes: the number is the position on the circle of fifths, A is minor, B is major. Keys next to each other on the wheel mix well. Tap the wheel to switch every label between codes and key names (8A ↔ A minor).
Groovelock uses the spelling DJ software prints on the wheel: D♭, E♭, F♯, A♭, B♭. Same notes, standard spelling.
Not yet. LOCK holds the current reading until you tap LOCK again, or tap the locked key or tempo to release it.
No. Everything runs on the phone. No audio, no recordings and no analytics leave the device. TestFlight beta builds send only the answers you choose to give on the feedback card; see the privacy policy.
Purchases are handled by Apple: go to reportaproblem.apple.com, sign in and choose the purchase. We don't see or control refunds, but if something isn't working we would like to know, so we can fix it.
In progress. Email us and we will let you know when it ships.
Found a track it gets wrong, or have an idea? Email support@groovelock.app with the track name, roughly where you were (booth, floor, at home), which mode you used and what the app showed — that is all we need.