./../../src/instrument.lsp

## instrument/default-chord-function [ Functions ]

[ Top ] [ instrument ] [ Functions ]

FUNCTION

     If an instrument is able to play chords, a function must be defined to
     select pitches from a list that it can play as a chord. This function (as a
     symbol) is passed as a slot to the instrument instance.

     This is the default function. It returns a 2-note chord with the pitch at
     index plus that below it, or that above it if there are no lower pitches
     available. Or it just returns a single-pitch chord object if neither of
     those cases are possible.

     NB: The arguments are supplied by slippery chicken when it calls the
         function.

ARGUMENTS

     - The current number from the pitch-seq. Currently ignored by default.
     - The index that the first argument was translated into by the offset and
       scaler (based on trying to get a best fit for the instrument and set).
       This can be assumed to be a legal reference into pitch-list as it was
       calculated as fitting in pitch-seq::get-notes.  (zero-based.)
     - The pitch-list created from the set, taking into account the instrument's
       range and other notes already played by other instruments.
     - The current pitch-seq object. Currently ignored by default.
     - The current instrument object. Currently ignored by default.
     - The current set object. Currently ignored by default.

RETURN VALUE

     A chord object.

SYNOPSIS

    (defun default-chord-function (curve-num index pitch-list pitch-seq instrument
                                   set)

## instrument/in-range [ Methods ]

[ Top ] [ instrument ] [ Methods ]

FUNCTION

     Checks whether a specified pitch falls within the defined range of a given
     instrument object or not.

ARGUMENTS

     - An instrument object.
     - A pitch item (pitch object or note-naem symbol).

OPTIONAL ARGUMENTS

     - T or NIL to indicate whether the pitch specified ist to be compared with
       the given pitch object's sounding or written range. T = Sounding.
       Default = NIL. If T, a secondary NIL is also returned to indicate that
       the specified pitch is neither too high nor too low.

RETURN VALUE

     Returns T if the specified pitch falls between the
     lowest-sounding/lowest-written and the highest-sounding/highest-written
     pitches of the given pitch object.

     If the specified pitch is outside of the range, an additional value of 0 or
     1 is also returned to indicate whether the specified pithc is too high (1)
     or too low (0).

EXAMPLE

    ;; Determine if a pitch provided as a note-name symbol falls within the written
    ;; range of a non-transposing instrument
    (let ((i1 (make-instrument 'inst1 :lowest-written 'bf3 :highest-written 'a6)))
      (in-range i1 'c4))

    => T, NIL

    ;; Determine if a pitch provided as a note-name symbol falls within the
    ;; sounding range of a transposing instrument, using the optional argument T
    (let ((i2 (make-instrument 'inst1 :lowest-written 'fs3 :highest-written 'c6
                               :transposition 'BF)))
      (in-range i2 'c6 T))

    => NIL, 1

    ;; A pitch object can be used as the specified pitch
    (let ((i2 (make-instrument 'inst1 :lowest-written 'fs3 :highest-written 'c6
                               :transposition 'BF)))
      (in-range i2 (make-pitch 'd6)))

    => NIL, 1

SYNOPSIS

    (defmethod in-range ((ins instrument) pitch &optional sounding)

## instrument/make-instrument [ Functions ]

[ Top ] [ instrument ] [ Functions ]

FUNCTION

     Create an instrument object, specifying the values for a number of
     parameters for describing characteristics of a given instrument, such as
     lowest and highest pitch, transposition, clefs used by the instrument etc.

     NB: The user will generally define instruments will in the context of the
     make-instrument-palette function and added directly to the
     +slippery-chicken-standard-instrument-palette+ parameter of the file
     instruments.lsp, using the keyword structure shown below in the OPTIONAL
     ARGUMENTS.

ARGUMENTS

     - A symbol that is the instrument ID.

OPTIONAL ARGUMENTS

     &key arguments:
     - :staff-name. String. This is the unabbreviated instrument name that will
       be used for the first page of printed scores.
     - :staff-short-name. String. This is the abbreviated instrument name that
       will be used for subsequent pages of printed scores.
     - :lowest-written. Note-name symbol. This is the lowest written pitch
       available on the given instrument. Defaults to NIL. A user may only
       define either the lowest-written value or the lowest-sounding value. If a
       lowest-written value is given, the method automatically determines the
       lowest-sounding value based on the lowest-written value and the
       transposition value.
     - :highest-written. Note-name symbol. This is the highest written pitch
       available on the given instrument. Defaults to NIL. A user may only
       define either the highest-written value or the highest-sounding value. If
       a highest-written value is given, the method automatically determines the
       highest-sounding value based on the highest-written value and the
       transposition value.
     - :lowest-sounding. Note-name symbol. This is the lowest sounding pitch
       available on the given instrument. Defaults to NIL. A user may only
       define either the lowest-sounding value or the lowest-written value. If a
       lowest-sounding value is given, the method automatically determines the
       lowest-written value based on the lowest-sounding value and the
       transposition value.
     - :highest-sounding. Note-name symbol. This is the highest sounding pitch
       available on the given instrument. Defaults to NIL. A user may only
       define either the highest-sounding value or the highest-written value. If
       a highest-sounding value is given, the method automatically determines
       the highest-written value based on the highest-sounding value and the
       transposition value.
     - :transposition. Note-name symbol. This is the key of the given instrument
       (such as the "B-flat" of the "B-flat clarinet"), given as a note-name
       symbol (such as 'BF for B-flat). If a value is only given for the
       :transposition argument but not for the :transposition-semitones
       argument, and there are multiple semitone transposition options for the
       key specified, the method will choose the most common semitone
       transposition for that given key. NB: When using keyword argument
       :transposition rather than :transposition-semitones, sc will have a
       warning printed by cm with indications as to which direction the
       transposition has been undertaken.
     - :transposition-semitones. Integer (positive or negative). The number of
       semitones lower that a given instrument sounds than written, e.g. -2 for
       B-flat Clarinet. If a value is only given for the
       :transposition-semitones argument but not for the :transposition
       argument, the method will automatically determine the key for the
       :transposition argument. The listener will drop into the debugger with an
       error if a key is given for the :transposition argument and the number
       specified for the :transposition-semitones does not correspond with that
       key.
     - :starting-clef. Symbol. This value determines the first clef that a given
       instrument is to use if that instrument can use different clefs. For a
       list of available clefs see the :clefs argument below.
       Default = 'treble.
     - :clefs. List of symbols. All clefs that a given instrument may use in the
       course of a piece. Clefs available are treble, alto, tenor, bass,
       percussion, double-treble, and double-bass. Clefs are to be given in
       order of preference. Defaults automatically to the value given to
       :starting-clef if no other clefs are specified. NB: If a separate list is
       indeed given here, the method will automatically add the value for
       :starting-clef as well, should it have been omitted. In this case, a
       warning will also be printed.
     - :clefs-in-c. List of symbols. Similar to :clefs, but designates which
       clefs an instrument uses in a C-score; for example, bass clarinet may
       notated in bass cleff for sounding pitches though it is standardly
       notated in treble clef for written pitches. For a list of clefs available
       see the :clefs argument above.
     - :largest-fast-leap. Number. This value indicates the largest interval, in
       semitones, that a player can feasibly perform at a fast tempo on the
       given instrument. Default = 999. "Fast" here is determined for the whole
       piece by the slippery-chicken class's fast-leap-threshold slot.
     - :score-write-in-c. T or NIL. Determines whether the musical material for
       the given instrument should be printed in C.  T = print in C.
       Default = NIL.
     - :score-write-bar-line. Integer. This argument is used for indicating
       system-grouping in the printed score. The given integer specifies how
       many instruments above this one should be grouped together with an
       unbroken bar-line. Default = 1.
     - :midi-program. Integer. The number of the MIDI program to be used for
       playing back this instrument. Default = 1.
     - :chords. T or NIL. Indicates whether the given instrument is capable of
       playing chords (starting with 2-note simultaneities, but not
       multiphonics).
     - :subset-id. Symbol, string, number, or NIL.  Indicates the ID of a
       specific subset of the current set to which the instrument's pitch
       selection is limited.  No error will occur if no subset with this ID
       exists in a given set, i.e. some may include this subset, some may not
       and everything will function correctly--if the specified subset is not
       present in the current set the pitch selection routine will select from
       the whole set.  In every case however, the usual set limiting according
       to instrument range etc. will also apply.  Default = NIL.
     - :microtones. T or NIL. Indicates whether the instrument can play
       microtones. T = can play microtones. Default = NIL. NB: If this value is
       set to T, a separate :microtones-midi-channel must be specified; this can
       be done for the given instrument object in the :ensemble block of the
       make-slippery-chicken function.
     - :missing-notes. A list of note-name symbols. This is a list of any notes
       which the given instrument can't play, for example certain
       quarter-tones. These are to be given by the user as written-pitch
       note-name symbols, but are always stored by the method as sounding
       pitches.
     - :prefers-notes. Symbol. 'high, 'low or NIL. This value indicates whether
       to give preference, when choosing notes for the given instrument, to
       pitches from the upper or lower end of the instrument's range. When NIL,
       preference is given to notes from its middle register. Default = NIL.
     - :chord-function. If the given instrument can play chords then it will
       need a reference to a function that can select chords for it. NB This
       should be a symbol not a function object; thus, 'my-fun not
       #'my-fun. Default = NIL.

RETURN VALUE

     Returns an instrument object.

EXAMPLE

    ;; Make-instrument for the flute:
    (make-instrument 'flute :staff-name "Flute" :staff-short-name "Fl."
                     :lowest-written 'c4 :highest-written 'd7
                     :starting-clef 'treble :midi-program 74 :chords nil
                     :microtones t :missing-notes '(cqs4 dqf4))

    =>
    INSTRUMENT: lowest-written:
    PITCH: frequency: 261.626, midi-note: 60, midi-channel: 0
    [...]
    , highest-written:
    PITCH: frequency: 2349.318, midi-note: 98, midi-channel: 0
    [...]
    lowest-sounding:
    PITCH: frequency: 261.626, midi-note: 60, midi-channel: 0
    [...]
    , highest-sounding:
    PITCH: frequency: 2349.318, midi-note: 98, midi-channel: 0
                starting-clef: TREBLE, clefs: (TREBLE), clefs-in-c: (TREBLE)
                prefers-notes: NIL, midi-program: 74
                transposition: C, transposition-semitones: 0
                score-write-in-c: NIL, score-write-bar-line: 1
                chords: NIL, chord-function: NIL,
                total-bars: 0 total-notes: 0, total-duration: 0.0
                total-degrees: 0, microtones: T
                missing-notes: (CQS4 DQF4), subset-id: NIL
                staff-name: Flute, staff-short-name : Fl.,
                largest-fast-leap: 999
    [...]
    NAMED-OBJECT: id: FLUTE, tag: NIL,
    data: NIL

    ;; A make-instrument for the b-flat bass clarinet
    (make-instrument 'bass-clarinet :staff-name "Bass Clarinet" :lowest-written 'c3
                     :highest-written 'g6 :staff-short-name "Bass Cl."
                     :chords nil :midi-program 72 :starting-clef 'treble
                     :microtones t :prefers-notes 'low
                     :missing-notes '(aqs4 bqf4 bqs4 cqs5 dqf5 gqf3 fqs3 fqf3 eqf3
                                      dqs3 dqf3 cqs3)
                     :clefs '(treble) :clefs-in-c '(treble bass)
                     :transposition-semitones -14)

    =>
    INSTRUMENT: lowest-written:
    PITCH: frequency: 130.813, midi-note: 48, midi-channel: 0
    [...]
    , highest-written:
    PITCH: frequency: 1567.982, midi-note: 91, midi-channel: 0
    [...]
                lowest-sounding:
    PITCH: frequency: 58.270, midi-note: 34, midi-channel: 0
    [...]
    , highest-sounding:
    PITCH: frequency: 698.456, midi-note: 77, midi-channel: 0
    [...]
    NAMED-OBJECT: id: BASS-CLARINET, tag: NIL,
    data: NIL

SYNOPSIS

    (defun make-instrument (id &key
                            staff-name
                            staff-short-name
                            lowest-written
                            highest-written
                            lowest-sounding
                            highest-sounding
                            transposition
                            transposition-semitones
                            (starting-clef 'treble)
                            clefs
                            (largest-fast-leap 999)
                            score-write-in-c
                            (score-write-bar-line 1)
                            (midi-program 1)
                            chords
                            clefs-in-c
                            subset-id
                            microtones
                            missing-notes
                            prefers-notes
                            chord-function)

## instrument/prefers-high [ Methods ]

[ Top ] [ instrument ] [ Methods ]

FUNCTION

     Determine whether the PREFERS-NOTES slot of a given instrument object is
     set to 'HIGH.

ARGUMENTS

     - An instrument object.

RETURN VALUE

     Returns T if the PREFERS-NOTES slot of the given instrument object is set
     to 'HIGH, otherwise NIL.

EXAMPLE

    ;; Returns T if the PREFERS-NOTES slot of the given instrument object is set to
    ;; 'HIGH
    (let ((i1 (make-instrument 'inst :prefers-notes 'high)))
      (prefers-high i1))

    => T

    ;; Returns NIL if the PREFERS-NOTES slot of the given instrument object is not
    ;; set to 'HIGH
    (let ((i1 (make-instrument 'inst1))
          (i2 (make-instrument 'inst2 :prefers-notes 'low)))
      (print (prefers-high i1))
      (print (prefers-high i2)))

    =>
    NIL
    NIL

SYNOPSIS

    (defmethod prefers-high ((ins instrument))

## instrument/prefers-low [ Methods ]

[ Top ] [ instrument ] [ Methods ]

FUNCTION

     Determine whether the PREFERS-NOTES slot of a given instrument object is
     set to 'LOW.

ARGUMENTS

     - An instrument object.

RETURN VALUE

     Returns T if the PREFERS-NOTES slot of the given instrument object is set
     to 'LOW, otherwise NIL.

EXAMPLE

    ;; Returns T if the PREFERS-NOTES slot of the given instrument object is set to
    ;; 'LOW
    (let ((i1 (make-instrument 'inst :prefers-notes 'low)))
      (prefers-low i1))

    => T

    ;; Returns NIL if the PREFERS-NOTES slot of the given instrument object is not
    ;; set to 'LOW
    (let ((i1 (make-instrument 'inst1))
          (i2 (make-instrument 'inst2 :prefers-notes 'high)))
      (print (prefers-low i1))
      (print (prefers-low i2)))

    =>
    NIL
    NIL

SYNOPSIS

    (defmethod prefers-low ((ins instrument))

## instrument/set-prefers-high [ Methods ]

[ Top ] [ instrument ] [ Methods ]

DATE

     05 Feb 2011

FUNCTION

     Sets the PREFERS-NOTES slot of the given instrument object to 'HIGH.

ARGUMENTS

     - An instrument object.

OPTIONAL ARGUMENTS

     (- optional ignore argument; for internal use only).

RETURN VALUE

     Returns symbol HIGH.

EXAMPLE

    ;; Returns symbol HIGH by default
    (let ((i1 (make-instrument 'inst)))
      (set-prefers-high i1))

    => HIGH

    ;; Create an instrument object with only an ID, print the PREFERS-NOTES slot to
    ;; see that it is NIL by default, apply the set-prefers-high, and print the
    ;; slot again to see the changes
    (let ((i1 (make-instrument 'inst)))
      (print (prefers-notes i1))
      (set-prefers-high i1)
      (print (prefers-notes i1)))

    =>
    NIL
    HIGH

    ;; Reset to HIGH from LOW
    (let ((i1 (make-instrument 'inst :prefers-notes 'low)))
      (print (prefers-notes i1))
      (set-prefers-high i1)
      (print (prefers-notes i1)))

    =>
    LOW
    HIGH

SYNOPSIS

    (defmethod set-prefers-high ((ins instrument) &optional ignore)

## instrument/set-prefers-low [ Methods ]

[ Top ] [ instrument ] [ Methods ]

DATE

     05 Feb 2011

FUNCTION

     Sets the PREFERS-NOTES slot of the given instrument object to 'LOW.

ARGUMENTS

     - An instrument object.

OPTIONAL ARGUMENTS

     (- optional ignore argument; for internal use only).

RETURN VALUE

     Returns symbol LOW.

EXAMPLE

    ;; Returns symbol LOW by default
    (let ((i1 (make-instrument 'inst)))
      (set-prefers-low i1))

    => LOW

    ;; Create an instrument object with only an ID, print the PREFERS-NOTES slot to
    ;; see that it is NIL by default, apply the set-prefers-low, and print the
    ;; slot again to see the changes
    (let ((i1 (make-instrument 'inst)))
      (print (prefers-notes i1))
      (set-prefers-low i1)
      (print (prefers-notes i1)))

    =>
    NIL
    LOW

    ;; Reset to LOW from HIGH
    (let ((i1 (make-instrument 'inst :prefers-notes 'high)))
      (print (prefers-notes i1))
      (set-prefers-low i1)
      (print (prefers-notes i1)))

    =>
    HIGH
    LOW

SYNOPSIS

    (defmethod set-prefers-low ((ins instrument) &optional ignore)

## instrument/transposing-instrument-p [ Methods ]

[ Top ] [ instrument ] [ Methods ]

FUNCTION

     Determine whether a given instrument object defines a transposing
     instrument.

ARGUMENTS

     - An instrument object.

OPTIONAL ARGUMENTS

     - ignore-octaves. T or NIL to indicate whether instruments that transpose
       at the octave are to be considered transposing instruments.
       T = instruments that transpose at the octave are not considered
       transposing instruments. Default = T.

RETURN VALUE

     Returns T if the given instrument object defines a transposing instrument,
     otherwise NIL.

EXAMPLE

    ;; Returns NIL if the instrument is not a transposing instrument
    (let ((i1 (make-instrument 'instrument-one)))
      (transposing-instrument-p i1))

    => NIL

    ;; Returns T if the instrument object has been defined using a non-NIL value
    ;; for :transposition
    (let ((i2 (make-instrument 'instrument-two :transposition 'bf)))
      (transposing-instrument-p i2))

    => T

    ;; Returns T if the instrument object has been defined using a non-0 value for
    ;; :transposition-semitones
    (let ((i3 (make-instrument 'instrument-two :transposition-semitones -3)))
      (transposing-instrument-p i3))

    => T

    ;; Setting the optional argument to NIL causes instruments that transpose at
    ;; the octave to return T.
    (let ((i3 (make-instrument 'instrument-two :transposition-semitones -12)))
      (transposing-instrument-p i3))

    => NIL

    (let ((i3 (make-instrument 'instrument-two :transposition-semitones -12)))
      (transposing-instrument-p i3 nil))

    => T

SYNOPSIS

    (defmethod transposing-instrument-p ((ins instrument)
                                         &optional (ignore-octaves t))

## linked-named-object/instrument [ Classes ]

[ Top ] [ linked-named-object ] [ Classes ]

NAME

     instrument

     File:             instrument.lsp

     Class Hierarchy:  named-object -> linked-named-object -> instrument

     Version:          1.0.0-beta1

     Project:          slippery chicken (algorithmic composition)

     Purpose:          Implementation of the instrument class which defines
                       musical instrument properties like range and
                       collects/stores information about what the instrument
                       plays: how many notes, in how many bars etc.

     Author:           Michael Edwards: m@michael-edwards.org

     Creation date:    4th September 2001

     $$ Last modified: 14:11:49 Thu Apr 19 2012 BST

     SVN ID: $Id: instrument.lsp 1764 2012-05-17 11:49:59Z medward2 $