Two songs of different musical keys, when mixed together, can be a symphony, or a disaster. Songs of identical pitch blend together well, but there are 24 basic scales (major and minor), so there's 553 possible combinations in your collection. There's a model for choosing tunes in other keys that will be harmonically balanced. Read on!
DJTools is an iPhone app with tools designed for experienced DJs wanting a handy device to calculate key/tempo, that also provides information on harmonic keys.
- Key identification tool
- BPM identification tool
- Displays other keys that will mix harmonically with the selected key
- Alternate key code format to simplify harmonic mixing
- Flashlight for fiddling with sound equipment when it's dark
- No "scratch" gimmicks, hands-in-the-air sample players and other tat
I have found the most complex algorithms are incapable of finding the correct key in dance music with any accuracy. Computers can't work it out when there are gaps in the musical scale, not like we can. A recent study on DJTechTools found the most common applications between 20%-40% accurate. So, more than half your tunes will be marked incorrectly.
For this reason, this app does NOT tell you what key a tune is in automatically, it will NOT scan your iTunes folder and mark up tunes. This app also doesn't play music, you need your own DJ equipment, decks, laptop etc. Much in the same way that a calculator won't do your tax returns for you.
This app WILL help you identify the key of a tune by playing a chord in that key. You have to do the clever bit, listen to the chords, compare and decide on the key yourself. You should have an understanding of key, scales, pitch and tempo before approaching this. Trust me, even if you're tone deaf, you're still infinitely better at identifying a song's key than a computer is. You will do well to learn about it. This app will help you do that. I'll be publishing tutorials on my website if you are still baffled.
The BPM analysis is similarly manual, and involves tapping the screen to the beat for a few seconds.
I designed this tool so I could play a tune, work out the BPM and key quickly, get my marker out, and mark up the label. Over all, this is designed for DJs, it will not MAKE you a DJ by doing the hard bits for you, but it will enhance your arsenal of tricks, and offer some creative ways for experienced DJs to fine-tune their art, mash up tunes, select fitting a capellas, etc.
I've incorporated a flashlight into the app, as I spend a lot of time trying to see what I'm doing when cabling, swapping gear out etc, and thought it would be useful not to swap to a different app to enable the flashlight on my phone.