ImmerGround for iPhone, iPad and Mac
Three ways to find the tempo
- Tap. Tap the pad, or press T or Space, on every beat. Four taps give a reading and eight settle it. A tap that lands twice or a beat you miss is ignored rather than dragging the number around.
- Song. Drop in an MP3, WAV, AAC or FLAC file. The finder measures how sharply the sound changes every 10 milliseconds, finds the pulse that repeats most strongly, then fits the beat across the whole song to a hundredth of a BPM. It also reads the key, draws the bar lines over the song and can play it back with a click on every beat.
- Mic. Play any music out loud, from a streaming app, a turntable or a band, and press Start listening. It reads the last twelve seconds once a second and shows Locked when the number holds still.
Half time and double time
A beat can be counted at two speeds, and both are correct in a way: drum and bass at 174 is also a pulse at 87, and dubstep is counted at 140 while it feels like 70. The finder picks the count most DJs use and shows the other two under the number. If your software counts the track differently, press ÷2 or ×2 and the beat lights follow.
Typical tempos by genre
| Genre | BPM | Note |
|---|---|---|
| Hip hop | 80 to 100 | Boom bap sits in the low 90s |
| Reggaeton | 88 to 100 | The dembow rhythm, often 95 |
| Pop | 100 to 130 | Wide; many hits sit near 120 |
| House | 118 to 128 | Deep house lower, tech house higher |
| Techno | 125 to 140 | Harder styles run past 140 |
| Trance | 128 to 140 | |
| Dubstep | 140 | Counted 140, feels like 70 (half time) |
| Trap | 130 to 160 | Half-time feel, so it can read as 65 to 80 |
| Drum and bass | 170 to 178 | Can read as 85 to 89 (half time) |
The key and the Camelot wheel
The key comes from the notes the song leans on most, with the bass counted extra because that is where the home note usually sits. It is a strong guess rather than a certainty: a minor key and its relative major use the same notes, so the finder shows both, such as A minor or C major. On the Camelot wheel those two share a number (8A and 8B), and tracks with the same number, or one step either side, mix without clashing. For the key on its own, the song key finder uses the same engine and adds the key section by section, the tuning, a key from typed chords, a whole folder at once, and a Camelot wheel that lists what mixes with each key.
Put the tempo to work
Tempo matters for visuals too. The free live visualizer reacts to the beat of whatever you play into it, and the free VJ loops are cut at 120 BPM so they sync in Resolume at any tempo. In the ImmerGround app, beats drive effects on your own clips and photos live, with no tempo to set.
Questions
Is this BPM finder free, and does my song get uploaded?
It is free with no account. Songs are decoded and analysed inside your browser and the microphone is read the same way; nothing is uploaded or recorded.
How accurate is it?
On a song with a steady beat it lands within a few hundredths of a BPM, so a 124 BPM house track reads 124. Live recordings with a drifting tempo get an average and a range. Press Play with click to hear the detected beat against the song.
Why does it say 87 when the track is 174?
Half time and double time are the same pulse counted two ways, and some tracks read either way. The finder shows both under the number; press ÷2 or ×2 to switch. Drum and bass is usually counted around 174, dubstep and trap around 140.
Can I find the BPM of a song on Spotify, Apple Music or YouTube?
Yes: switch to Mic, press Start listening and play the song out loud near your device. A web page cannot read another app's audio directly, but the microphone hears it. It settles in about ten seconds.
Which files can I drop in?
MP3, WAV, AAC (M4A) and FLAC work in every current browser. OGG works in Chrome and Firefox but not Safari. The first twelve minutes of a longer file are analysed.
What does the key and the Camelot code mean?
The key is the scale the song uses most, found from the notes it plays. The Camelot code puts keys on a wheel: tracks with the same code, or one step away, mix without clashing. A minor and its relative major share a number, such as 8A and 8B.