1. Music and Audio Computing I 216-306A
Prof. Marcelo M. Wanderley
Week 7

2. Music and Audio Computing I
Concepts, algorithms, data structures, and programming techniques for the development of music and audio software, ranging from musical instrument design to interactive music performance systems.
Student projects will involve the development of various music and audio software applications.
October 18th week 7
306A - Music and Audio Computing

3. 306A - Music and Audio Computing
Previous four weeks
Introduction to MAX (Alex Burton)
General features: objects, messages, connections, arguments…
Objects: coll, table value, delay, metro, counter, random, split, gate, select, send & receive, if, midi objects, operators, …
First assignment: algorithmic project
October 18th week 7
306A - Music and Audio Computing

4. 306A - Music and Audio Computing
Previous four weeks
Week 2
Data storage: coll, table. value
data sharing
Week 3
Basic mathematical operations
Decisions: if-then, split, gate, select
Week 4
Abstractions and sub-patches
send & receive
October 18th week 7
306A - Music and Audio Computing

5. 306A - Music and Audio Computing
Rest of the Course
Total duration: 13 weeks
2 assignments - 20% each
2 tests - 10% each
1 project - 40%
Main Topics to be covered: Time management, mathematical functions, sequencing, design/simulation of interactive instruments…
October 18th week 7
306A - Music and Audio Computing

6. 306A - Music and Audio Computing
Week 7 (this week)
Topic: Time and Math managing in MAX
Objectives:
Understanding of the various ways to manage time in MAX, the use of mathematical expressions using expr and if-then-else loops.
Objects to be used:
clocker, metro, counter, line, tempo,if, expr
Tutorials: tutorial 31 and tutorial 38
October 18th week 7
306A - Music and Audio Computing

7. (Real-) Time in computer music
Synchronization
Between processes
To external events, e.g. MIDI timecode
Triggering of events
simultaneous or with delay
Repetition (with variations: e.g. tutorial 23)
October 18th week 7
306A - Music and Audio Computing

8. 306A - Music and Audio Computing
Time in MAX
Time code formats in MAX
milliseconds (most usual)
metro, count, clocker…
beats (ticks: fractions of a beat)
tempo
SMPTE code -> synchronization
October 18th week 7
306A - Music and Audio Computing

9. 306A - Music and Audio Computing
Time management in MAX
MAX SCHEDULER
timing interval: 1 to 20 ms (accuracy versus CPU efficiency)
Interruption: stop scheduler ->
Stack overflow error, e.g in a loop that overloads MAX (repetitions in less than 1 ms)
Solution: resume (from the edit menu) restarts the scheduler (MAX 4)
October 18th week 7
306A - Music and Audio Computing

10. 306A - Music and Audio Computing
Timing objects in MAX
Basic objects: metro, clocker…
timeline object
Sequencers: seq, follow, mtr, detonate
OMS timing: clock source useful for synchronization of multiple sources to a single clock.
MAX objects: timein, timeout, setclock
October 18th week 7
306A - Music and Audio Computing

11. Timing objects in MAX: Hands on
Check patches week7-clocker, week7-counter, week7-line and week7-tempo.
Compare the 3 different ways of implementing the same counter.
Verify the difference between the counters in milliseconds and in beats (clocker, metro + counter, line versus tempo)
Check the different possibilities in counter, line and tempo.
October 18th week 7
306A - Music and Audio Computing

12. Loops in MAX
Repeated actions (common in computer music) If, For (While)
Loops with decisions: metro, clocker, random and sel, if…
Instantaneous loops: as fast as possible
message boxes, uzi (machinegun bangs)
if object: if-then-else loop
October 18th week 7
306A - Music and Audio Computing

13. 306A - Music and Audio Computing
Debugging in MAX
Remember!!
Clean patches with sub-patches and abstractions
Attention to message order!! Right-to-left, bottom-up
Debugging using simple objects: number boxes, button, print, capture and Text
October 18th week 7
306A - Music and Audio Computing

14. 306A - Music and Audio Computing
Debugging in MAX
TRACE option (MAX menu) traces messages as they are passed in a patch)
Trace enabling (without overdrive)
You can trace your messages
step by step (cmd T),
using automatic steps,
setting breakpoints…
Max window indicates each step!!
(try week7 trace patches)
October 18th week 7
306A - Music and Audio Computing

15. 306A - Music and Audio Computing
Math in MAX
Basic objects: operators
expr object -> math similar to C programming language
Ex. "pow": x to the power of y
Additional math functions available using “expr”: abs, min, max, sin, cos, tan, log10, ln, random...
October 18th week 7
306A - Music and Audio Computing

16. 306A - Music and Audio Computing
Math in MAX: Hands on
Open patches: week7-expr and week7-if
Compare the two implementations of the same mathematical operations using individual objects and the expr object
Remember that using simple objects implies taking into account the right-to- left, bottom-up flow of messages in MAX!!
October 18th week 7
306A - Music and Audio Computing