reality jockey
November 17, 2008 5:45 PM   Subscribe

RjDj "is a music application for the iPhone. It uses sensory input to generate and control the music you are listening to. RjDj is mainly listened to with headphones. Think of it as the next generation of walkman or mp3 player." l Michael Breidenbruecker initiated the project, now joined by a team of musical and technological thinkers and coders l "What it’s really about is a new approach to how to listen to music, how to develop musical tools, and how communities own and share that work."

The application is difficult to describe and on paper it sounds sort of silly (see the video below for a convincing demonstration). Using the iPhone’s built in microphone, the application listens for ambient noise which it then modifies and infuses into an automatically generated dynamic soundtrack.

You can download the full version for $2.99 here, or you can try out the free version (which only has one ’scene’).

How to Create Scenes (And incidentally, you can work on scenes with a laptop even if you don’t own an iPhone.)

Mentioned previously here and in AskMe.
posted by nickyskye (21 comments total) 28 users marked this as a favorite
RjDj is one of my favorite iPhone apps. At work I'll aim the iPhone's mike toward the middle of the office and run Echolon or World Quantize while wearing very efficient earplug style earphones (approx. 24 dB noise dampening). The only audible input becomes a heavily processed version of ambient noise, turning all the dropped boxes, phone rings, and shouted conversations into an indecipherable, continuously shifting wash of beat patterns and ocean waves. And since it's constructed out of the ambient noise, it cancels that noise much more effectively than playing music does.

I don't always listen to it, but when I need to concentrate and am in no mood for my usual working music, it's ideal.
posted by ardgedee at 5:59 PM on November 17, 2008

This is by far the most compelling and appealing app I've seen thus far, at least for me personally...Yet another thing to look forward to in my agonizing 2 months until my contract renewal!
posted by rollbiz at 6:07 PM on November 17, 2008

Makezine has a great article about the original application that Rjdj is built on (called 'PD'), and how to hack that.
posted by tybeet at 6:13 PM on November 17, 2008

THIS IS COOL. And a fuck of a lot more useful to me than this app.
posted by gman at 6:17 PM on November 17, 2008

I love this app. I keep a clean iPhone; if I don't use an app for more than about two weeks, it gets deleted. This one has been a fixture, and will be for a long time.

"Eargasm" is like living in a Boards of Canada song.
posted by kaseijin at 6:47 PM on November 17, 2008

It is interesting to see that rjdj uses pd internally. I use pd alot, mainly as a scratchpad for musical or algorithmic ideas (the box and line representation fits my mental image of a flowchart pretty well, and fits my creative mindset better than writing code in a textual language does). There is a project to convert a experimental electronic repertory into Pure Data patches. It is simultaneously amazing and kind of sad that we carry around devices that are capable of so much, and for the most part, do so very little with them. Here I sit in front of a device that I usually use as a fancy upgrade to a magazine and postal system, and I am reminded that it can do things the heroes of electronic music could only dream of in their day.

By the way, tybeet, to be pedantic the article has no information on hacking pd (though hacking and extending pd is easy, if you can handle programming in c and/or tcl), but rather shows how to use pd for its intended purpose, which is using the patching environment to create audio applications.
posted by idiopath at 7:06 PM on November 17, 2008

This is totally fascinating. Walking around a coffeeshop that has Sinatra playing is a trippy experience. With the free version, it echoed espresso pulls and knocks with a weirdly haunting undercurrent of Frank Sinatra's voice.

Buying the full version shortly. =)
posted by aliceinreality at 7:10 PM on November 17, 2008

$2.99. Good grief! I may not have my jetpack, but this is most definitely the future.
posted by nosila at 7:47 PM on November 17, 2008

I had to download this as soon as I saw this post, and I'm not disappointed. This app is amazing.
posted by painquale at 8:35 PM on November 17, 2008

i'm with you painquale. the span of me not knowing anything about this, to actually buying it took less than 3 minutes. OH MY FUCKING GOD WORLDQUANTIFIER SOUNDS SO COOL WHEN I TYPE.
posted by Mach5 at 8:42 PM on November 17, 2008

err, quantizer
posted by Mach5 at 8:43 PM on November 17, 2008

Anyone know if this works on iPod Touch 2g? Help me justify a needless purchase!
posted by reishus at 9:46 PM on November 17, 2008

"Eargasm" is like living in a Boards of Canada song.

Curious what that means.
posted by nickyskye at 9:48 PM on November 17, 2008

Anyone know if this works on iPod Touch 2g?

There is a dialog about this if you scroll down the page.

"Unfortunately, the app is not compatible with the iPod touch, because it lacks a microphone. There are third-party mics, but none seems to be compatible with the new 2.x firmware."

"Earphones with a microphone input are going to be available soon from Apple. They will allow microphone input with the iPod Touch 2.0, so be on the lookout for when they start shipping."
posted by nickyskye at 9:58 PM on November 17, 2008

I'll wait for someone to come up with an open source version for Android.

Because I'm so Indy. I don't play with popular toys!
posted by delmoi at 10:15 PM on November 17, 2008

delmoi: It'll be quite a while before Google gets their shit together enough for an app like this to be remotely possible.

Audio manipulation is bad enough in normal Java, but at least you can get yourself raw audio out and write your own synthesis stack. On Android it's impossible.

You can't get live audio from the microphone, only record to a file. The MediaPlayer class can play recorded audio from a file in your bundle, but you can only instantiate ten at once (much less have them playing), and there is no mixing or anything. There's a more advanced and undocumented class called SoundPool that lets you change the playback rate, but that's it. You can also generate standard DTMF tones for pretend-telephony. There are no other ways to generate sound. It's not even good enough to do decent audio effects in games, much less synthesis.

The sandbox is a straightjacket. On the iPhone you can use existing libraries in any language that can be compiled to an ARM Mach-O binary (most all audio libraries). On Android you're restricted to JVM languages, and even if you found/wrote a decent synthesis library there's no way to hook it up to input or output.
posted by blasdelf at 2:49 AM on November 18, 2008

nickyskye- Boards of Canada song.
posted by gman at 4:29 AM on November 18, 2008 [1 favorite]

I actually took this app off my iPhone for a week or two, because I found that I was listening to it too much, at the expense of proper music. It's that good.

I especially like the World Quantizer scene, which imposes rhythms on the sounds it picks up, with louder sounds tending to end up as a regular beat, quieter sounds being put to use as syncopated percussion, and sounds the app doesn't fancy sampling overlaid with lots of delay. The way a sound will get picked up, used in the rhythm, dropped for a while only to return is amazing - it really transforms the experience of walking the streets, shifting sound through time and space, and throwing up wonderful coincidences - eg. yesterday I walked past a bus stop, and RjDj picked up the sound of two girls arguing, which went away for a couple of minutes, then returned at the exact moment I walked past the next bus stop, which was empty, but now, thanks to RjDj, haunted by the arguing girls from down the road. Audiopsychogeography-tastic!

It's worth jailbreaking your iPhone just to get the RjDj recordings on to your computer, and to install the thirty-odd extra themes available here (though some of them are a wee bit crashy).
posted by jack_mo at 5:37 AM on November 18, 2008 [1 favorite]

Holy crap. This is pretty amazing (just trying the free version at the moment.)

I'm not sure I like that every time my cubicle neighbor coughs, I hear it echoed for a few seconds... but maybe it fades into the background better that way. My own throat clearings are a little disconcerting.

My cube is right outside the kitchen, so I get lots of microwave beeps, dishes clanking, and faint conversation. But once lunch is over, I'm not sure there will be a lot of source noise. I'm realizing now that we have a pretty quiet office sometimes. I wonder what this will be like on the train. I'm finding myself making little noises - squeaking my soles of my boots, rocking in my office chair, etc. - just to see what happens. This might make me way more annoying to my coworkers.
posted by misskaz at 11:16 AM on November 18, 2008

I love this app! It's great for making sample-able material for music sequencing.
posted by noriyori at 11:20 AM on November 18, 2008

This app in general, and World Quantizer in particular, may find itself classified as a controlled substance at some point. It's messin' with my head, man!
posted by kcds at 5:43 PM on November 19, 2008

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