1. ISE-575 Presentation 1 Designing Smule’s iPhone Ocarina By Ge Wang Huihui Cheng 3/20/2011

2. Smule Ocarina What is Smule: An iPHONE App. A music instrument you can put in your pocket. A platform where people can share performance

3. Design Goal Goal: Create an expressive musical instrument. Preserve as much of the physical interaction as possible Enable new social musical experiences

4. Interface 4 hole English Pendant ocarina

5. Social Feature GPS information can be acquired when the performance is shared

6. What’s inside Sound synthesis takes place in real-time on the iPhone via Smule’s audio engine, using the ChucK programming language and runtime ChucK : Strongly-timed, Concurrent, and On-the-fly Audio Programming Language

7. About Chuck- Manipulate Time ChucK is a strongly-timed language, meaning that time is fundamentally embedded in the language. By default, ChucK provides these preset duration values: samp : duration of 1 sample in ChucK time ms : duration of 1 millisecond second : duration of 1 second minute : 1 minute hour : 1 hour day : 1 day week : 1 week // a duration of one secon 1::second => dur foo; // a point in time (duration of foo from now) now + foo => time later;

8. About Chuck- Unit Generator Unit Generators are function generators that output signals that can be used as audio or control signals. However, in ChucK, there is no fixed control rate. Any unit generator may be controlled at any rate. // instantiate a SinOsc, connect its output to dac's input SinOsc s => dac;  It is also possible to linearly chain many UGens together in a single statement. // connect SinOsc to Gain to reverb to dac SinOsc s => Gain g => JCRev r => dac;  parameters of unit generators may be controlled and altered at any point in time and at any control rate // set initial frequency to 440 hz 440 => s.freq; // let time pass for 1 second 1::second => now; // change the frequency to 880 hz 880 => s.freq

9. Reference http://ocarina.smule.com/ http://chuck.cs.princeton.edu/