Fantastic DJ app for iPhone stung by piracy

Music-tech entrepreneur Aviv Eyal, who's behind the excellent Livekick concert-tracking site, has a new project: a DJ app for the iPhone and iPod Touch called DJ Mixer Pro. (It was formerly known as DJ Player Pro, but the name has changed to avoid a conflict with another app.)

The concept is similar to Touch DJ, an Amidio app that I wrote about last month. While the iPhone naturally restricts you to playing one song at a time, these apps function like a virtual DJ booth, letting you play two tracks simultaneously, jump to any point in either track with a touch of your finger, crossfade between them, match beats, adjust tempos, and add various effects.

I was impressed by Touch DJ's technical capabilities, but DJ Mixer Pro is even more extensive. Amateurs like me will love the sync button: as you're playing one track, the sync button will adjust the speed of the second track and place the downbeats in the right place so they're synchronized. You can also adjust beats per minute (BPM), and DJ Mixer can change tempo without changing pitch, so your sped-up tracks don't sound like the Chipmunks. (If you want the Chipmunks, you can turn the pitch correction off.) The loop function is easier to use as well--you can select a specific number of beats in the song, rather than having to start and stop the loop with finger touches. This made it really easy for me to create a couple different loops of the gunshot chorus in MIA's "Paper Planes" (four and eight beats long). You can also do some interesting things bouncing between tracks--I created two separate loops of Nirvana's "All Apologies" and played them over each other. Finally, DJ Mixer offers more indicators about each track, including volume levels and colored bars to match each drumbeat. This video shows you more. Best of all, it's only half the price of Touch DJ--$9.99.

But there's one nagging usability issue: uploading music to the app is complicated. Apple currently does not allow other apps to access the iTunes playback app, and tracks need to be electronically manipulated before you can mix them. This means that users have to upload their music separately into DJ Mixer. This was also the case with Touch DJ, but where that app used a piece of desktop software to accomplish the task, DJ Mixer uses a Web server.

And therein lies the problem. According to Eyal, when DJ Mixer launched in late November (as DJ Player), the company's servers were inundated with users trying to upload songs to pirated versions of the app--he estimates that between 90 percent and 99 percent of the uploads were from users who didn't pay for the app. This created a lot of load on the servers, and hampered legitimate users.

So now, to upload your music to DJ Mixer, first you need to e-mail customer support with a copy of your receipt from the iTunes store or a screenshot showing your purchase history with the DJ Mixer app on it. Then you must go through a Web interface to perform the uploads. The company e-mails you back for each upload as it becomes ready, after which you have to open the app, hit "downloads," and enter your personal numeric code. Finally, you have to wait as the app downloads each song from the Web server and performs the necessary conversion--a process that takes about 15 or 20 seconds per song.

It's a pain, but the app is good enough that it's probably worth going through this process. You'll only have to do it once, and then you'll be set up for some pretty serious DJ'ing.