4 iOS Tools To Give You An Unfair Advantage In The DJ Booth

While I was loading tracks into various iOS DJing apps last week, I started wondering if there were apps that could help DJs work out the key and BPM of any music, not just digital files. Why would this be useful? Well, say you’re playing after a CD or vinyl DJ. Wouldn’t it be good to whip out your iPhone and quickly detect the BPM (and even the key) of the last track played, then effortlessly blend your next track in, perfectly harmonically matched and on the beat, as you take over digitally?

Or, if you’re a DJ who plays some music from digital, but you also use CDs and vinyl, wouldn’t it be nice to quickly “key” and BPM an old vinyl tune for easy mixing into your set, without having to rip it and run it through laptop key and BPM/DJ software? Turns out all of this is possible. Let’s look at some of your options:

Our best four BPM & key apps…

DJ Tempo

This is a simple but brilliant app from Mixed In Key to detect the BPM of any background audio.

You can choose how long to give the app for BPM analysis; the longer you select, the better chance you have of getting a more accurate reading.

When you press the “Analyze Tempo” button, a hypnotic, blue circular countdown is displayed, and after your selected period of time (anywhere from five to 20 seconds) a BPM (to two decimal places) is displayed.

Once the app had passed “go” by successfully detecting the easy BPMs on a few house tracks, I decided to throw everything at it including a shuffling live funk number, a sluggish reggae tune and some crazy fast drum & bass. The app was consistently accurate; even the drum & bass tracks were correctly analysed in the 174 BPM region. At a lower time threshold (less than ten seconds) the readings were slightly less reliable, but only on the more extreme tracks.

Seeing as it’s free, this app should be on all DJs’ iPhones / iPod Touch devices. What’s to lose?

Price: Free
Download from: App Store

Beat Control

This is another BPM detection app which can either take mic input (Auto) or finger tap as the method for calculation. I found the mic input method to be not as accurate as DJ Tempo, however the addition of tap tempo was useful if I wasn’t entirely convinced of the auto reading from this app (or any other, come to that)..

The tapping method is identical to how we used to count BPM manually with vinyl back in the day, but taking out any inaccuracies in counting or timing and doing the calculations. The BPM is calculated to one decimal place – again, not quite as accurate as DJ Tempo.

Price: Free
Download from: App Store

DJ Tools

This handy app was developed by a DJ, Pete Simpson, to help with manually keying his own library. While the interface may not be as slick as others, it is functional and if you get lost there’s a helpful guide on Pete’s site.

This app doesn’t actually calculate the BPM or detect the key for you, rather giving you the means to do so. (Its developer points out that auto key detection software often gets the key wrong anyway.)

For best results, you use the app to calculate the BPM first by tapping on the green display near the top. Once the BPM has been detected it is displayed in this section (no decimal place accuracy here I’m afraid).

Now you can use the key buttons below to play out piano chords in selected keys, to try and match the audio from the app to the track playing in the background. (That’s why you should match the BPM first; ideally, the piano chords will play at the BPM you’ve set.)

When a key button is pressed, the main display shows you the key, Camelot code and which keys/codes would mix with the selected key. Having both the key and Camelot code side by side is a welcome comparison, because over time you will probably start to learn the harmonic circle as a result.

If you’re not familiar with harmonic key detection or have no background in music, then this is a good tool to learn from. Incidentally, the app also has a “white-screen” flashlight which may be useful in low-light settings such as a club.

Price: US$0.99
Download from: App Store

Flail

Although at first glance this app may seem a curious choice as a tool for DJs, it does include BPM and harmonic key analysis.

The app is more of a musical play medium than anything else. However, upon swiping upwards on the bottom section of the display and pressing the Key tab you’re shown a mini keyboard, under which is the “get key & BPM from mic” button.

The next screen gives you four guesses as to what the key and tempo could be. By pressing one of the values you get to hear the key in question and then to decide whether this matches the track you can hear in the background. (This video does a better job at showing how you could use the app than a description can.)

You get a small choice of sounds, FX and other settings which make it more of a musical experience than a tool for analysing your music, hence the price difference between this app and DJ Tools. The app could also benefit from some more user help around the mic detection page, which is confusing.

Price: US$2.99
Download from: App Store

Conclusion

It’s not only DJs that some of these apps could be useful for. I can also see them being handy in-pocket solutions for lighting guys, many of whom execute light shows that rely on BPM sync. I am sure many lighting techs would find such apps useful, especially if they’re not close enough to glance over at any readouts of BPM, or to ask the DJ.

One limitation, by the way, is that while iOS apps can currently tell you BPM and key, they can’t do the same for music already on your device and record the findings directly to the audio file. That’s due to Apple’s restrictions on access to those files. Maybe in the future this will change, but right now it’s unlikely anyone will find a way to get around the limitation.

I have to end by pointing out that this is all far cry from those days I spent in the early 90s, scouring the chart pages of DJ Magazine for BPM data of tracks I owned…or even counting the BPM out using a 30-second timer on my watch! How times have changed…

Have you used any of these apps? Found an Android equivalent? Have we missed any out? Please let us know your thoughts in the comments.