1. The Art of Digital DJing
Mixing Music,Video, and Technology
Lecture 6. Mar 20, 2010
Sunday, March 21, 2010

2. Agenda
• Final Exam Details
• Intro to Video manipulation using
Quartz
• How to grab videos off YouTube
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Sunday, March 21, 2010

3. Final Exam
• Donʼt go to the big
Air Conditioned on
Lincoln!
•
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SUNDAY 3/28
• DJ Order is TBD
Sunday, March 21, 2010

4. Final Exam Notes
• Aim for 20min sets - have an intro and outro planned
• Practice - record yourself DJing 2-3 times and playback
in your car or iPod, ask yourself if you would rock this
mixtape! Note your trouble spots and where you can
improve on transitions/effects. See how you sound from
the audienceʼs perspective
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• Read the crowd and respond - eg if you need to take the
tempo/energy up, give yourself a few options. Or if a
song kills the dance floor, mix quickly out of it, etc
Sunday, March 21, 2010

5. Final Exam Grading Criteria
• Three main categories - 1) Technical 2) Creative, and 3) Presence and
your score is out of 100
• Technical: transitions (mixing/blending on phrases), use of controllers
(and not mouse), covering up mistakes well, executing effects, mixing in
key (or transitioning from one key to another) in a pleasing way (worth 35
points); proper EQing (eg no bass clashing).
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• Creative: flow - does the mix take you on a journey, build up, novel effects
and/or novel use of controller, basically, did you surprise us (in a good
way)? Original mashups and or improvisation - eg layering up a unique
3-4 (or more) clip creation in realtime (worth 35 points). Do your mashups
work?
• Presence - Are you looking at and engaging the crowd? Do you not look
like youʼre playing mindsweeper? Do they love you? (worth 35 points -
yes, you can score over 100)
Sunday, March 21, 2010

6. Video and DJing
eg http://vimeo.com/5616060
http://vimeo.com/430483
• Good tutorials on QC from DJ Shakinda in Ireland: http://vimeo.com/
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user233454/videos/page:3/sort:newest
• Free Quartz Compositions: http://www.quartzcompositions.com/
Sunday, March 21, 2010

7. Using QC and Video
• First Install QC by installing Xcode from Apple: http://
developer.apple.com/technologies/xcode.html
• Shakinda has some extra pointers and references:
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http://vimeo.com/704322
Sunday, March 21, 2010

8. Your first Quartz Composition
• Start with a blank
composition
• You can play with the
templates later when you
get more comfortable with
QC
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Sunday, March 21, 2010

9. Your first Quartz Composition
patch creator
• Open the “Patch Creator”
and find the “Billboard”
patch
• Billboard is under the
Category “Renderer”; we
need a renderer to display
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the output video
Sunday, March 21, 2010

10. Your first Quartz Composition
• Connect the “image” output
of your movie loader to the
“image” input of the
billboard
• Click on “viewer” and you
should see your movie clip
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playing
Sunday, March 21, 2010

11. Your first Quartz Composition
• Use the patch creator again and find
the “MIDI Controller Receiver” patch
and add that to your project. Once
youʼve added this patch, select it and
click on “Patch Inspector” from the
toolbar (or hit -2) - that will give you
settings for the patch. Choose “Learn
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Controller to Observe: and twiddle a
knob or hit a button on your MIDI
controller - you will see an output on the
patch show up for every control you
twiddle)
• Click on “viewer” and you should see
your movie clip playing
Sunday, March 21, 2010

12. Your first Quartz Composition
• Now decide how you want
your MIDI controller to modify
your image
• Hereʼs an easy but boring one
- connecting your controller
output to “Enable” on the
billboard, which means any
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positive value from your
controller means the video is
visible. If 0, then image is
hidden
Sunday, March 21, 2010

13. Effects
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• Something more interesting to control with your controller are Effects
• The above is an example of the effect of a Gaussian Blur. Here, the MIDI controller
to modify the “Radius” input of the Gaussian Blur Patch. MIDI controller values are
always 0-1, so Iʼve used a “Mathematical Expression” patch to multiply the
controller value by 50 (click patch inspector -> settings to edit expression).
• Play with other “filters” too find something you like. Remember that MIDI control
can tie to a control in Ableton if you map it to do so. Just have QC running when
youʼre using Ableton to see your controller control video AND something in Ableton
Sunday, March 21, 2010

14. Effects - Triggering
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• If you have a movie you want to re-trigger everytime you hit a controller (like a
pedal), you can use the controller to reset the time on a movie clip back to 0 with
every hit. By default, the movie loader patch will play at a constant rate. if you want
to re-trigger it, you will need to tell the movie loader to change itʼs “Timebase” to
Sunday, March 21, 2010