INTRODUCTION
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Isobar is a Python library for expressing and constructing musical patterns,
designed for use in algorithmic composition. It allows for concise construction,
manipulation and transposition of sequences, supporting scalar operations on
lazy patterns.

USAGE
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from isobar import *
from isobar.io.midiout import *

# create a repeating sequence with scalar transposition:
# [ 48, 50, 57, 60 ] ...
seqA = PSeq([ 0, 2, 7, 3 ]) + 48

# apply pattern-wise transposition
# [ 48, 62, 57, 72 ] ...
seqA = seqA + PSeq([ 0, 12 ])

# create a geometric chromatic series, repeated back and forth
seqB = PSeries(0, 1, 12) + 72
seqB = PPingPong(seqB)

# create an velocity series, with emphasis every 4th note,
# plus a random walk to create gradual dynamic changes
amp = PSeq([ 60, 40, 30, 40 ]) + PBrown(0, 1, -20, 20)

# a Timeline schedules events at a given BPM, sent over a specified output
timeline = Timeline(120)

midiout = MidiOut()
timeline.output(midiout)

# assign each of our Patterns to particular properties
timeline.sched({ 'note': seqA, 'dur': 1 })
timeline.sched({ 'note': seqB, 'dur': 0.25, 'amp': amp })

timeline.run()


EXAMPLES
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More examples are available in the 'examples' directory with this
distribution.

CLASSES
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Current class list:

	Chord
	Key
	Note
	Scale
	Timeline
	Clock

Pattern classes:

    CORE (pattern/core.py)
	Pattern        - generic pattern superclass
	PConst         - constant value
	PAdd           - add two patterns together (shorthand: patternA + patternB)
	PSub           - subtract pattern B from A (shorthand: patternA - patternB)
	PMul           - divide pattern A by B (shorthand: patternA / patternB)
	PDiv           - multiply pattern A by B (shorthand: patternA * patternB)

    SEQUENCE (pattern/sequence.py)
	PSeq           - sequence of fixed values (repeated N times)
	PSeries        - geometric series
	PLoop          - repeat an input pattern N times
	PCreep         - creep through an input pattern by N notes each step
	PStutter       - repeat each input value N times
	PWrap          - wrap values around a given range
	PPermut        - all permutations of a finite input pattern
	PDegree        - map values to a given Scale
    PImpulse       - generates an impulse every N steps
    PReset         - resets an input pattern when an impulse is received
    PSubsequence   - extracts a subsequence at a given index and length
    PArp           - generates arpeggios with a range of settings

    CHANCE (pattern/chance.py)
	PWhite         - white noise (uncorrelated values within a given range, int or float)
	PBrown         - brownian noise (random walk over a given range, int or float)
	PWalk          - random walk over a given input list
	PChoice        - random choice from a list
	PWChoice       - weighted random choice from a list
	PShuffle       - shuffle a finite input sequence
	PSkip          - skip over input values with some probability 
	PSelfIndex

    OPERATORS (pattern/operator.py)
	PDelay         - outputs the next value of an input pattern after N ticks
	PDiff          - difference between last two input values
	PAbs           - absolute value of an input pattern

    L-SYSTEMS (pattern/lsystem.py)
	PLSys          - integer sequence derived from Lindenmayer systems

    MARKOV (pattern/markov.py)
	PMarkov        - markov chain patterns

    WARPING AND AUTOMATION [EXPERIMENTAL] (pattern/warp.py)
	PWarp          - warp continuous values (abstract superclass)
	PWRamp         - warp on a linear ramp
	PWSine         - warp on a sine
	PAutomate      - superclass for continuous value automation (in development)

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BACKGROUND
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Isobar was first designed for the generative sound installation Variable 4:

	http://www.variable4.org.uk/news/

Many of the concepts behind Pattern and its subclasses are inspired by the
excellent pattern library of the SuperCollider synthesis language:

	http://supercollider.sf.net