Python库 | mingus-0.4.0.3.tar.gz

""" ================================================================================ Music theory Python package, chords module Copyright (C) 2008, Bart Spaans This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. ================================================================================ The chords module is a huge module that builds on the \ [refMingusCoreIntervals intervals] module. It can be used to generate and \ recognise a plethora of chords. The following overview groups some of the functions you are most likely to use together. == Generate Diatonic Chords == * Triads * triad * triads * Sevenths * seventh * sevenths == Generate Absolute Chords == * Triads * minor_triad * major_triad * diminished_triad * Sixths * minor_sixth * major_sixth * Sevenths * minor_seventh * major_seventh * dominant_seventh * minor_major_seventh * minor_seventh_flat_five * diminished_seventh * Ninths * minor_ninth * major_ninth * dominant_ninth * Elevenths * minor_eleventh * eleventh * Thirteenths * minor_thirteenth * major_thirteenth * dominant_thirteenth * Augmented chords * augmented_triad * augmented_major_seventh * augmented_minor_seventh * Suspended chords * suspended_second_triad * suspended_fourth_triad * suspended_seventh * suspended_fourth_ninth * suspended_ninth * Altered chords * dominant_flat_ninth * dominant_sharp_ninth * dominant_flat_five * sixth_ninth * hendrix_chord == Get Chords by Function == * Function * tonic and tonic7 * supertonic and supertonic7 * mediant and mediant7 * subdominant and subdominant7 * dominant and dominant7 * submediant and submediant7 * Aliases * I, II, III, IV, V, VI * ii, iii, vi, vii * I7, II7, III7, IV7, V7, VI7 * ii7, iii7, vi7 == Useful Functions == * determine - Can recognize all the chords that can be generated with from_shorthand (a lot) and their inversions. * from_shorthand - Generates chords from shorthand (eg. 'Cmin7') ================================================================================ """ import intervals import notes import diatonic from mt_exceptions import NoteFormatError # A cache for composed triads _triads_cache = {} # A cache for composed sevenths _sevenths_cache = {} # A dictionairy that can be used to present # lookup chord abbreviations. This dictionairy is also # used in determine_seventh() chord_shorthand_meaning = { # Triads "m" : " minor triad", "M" : " major triad", "" : " major triad", "dim" : " diminished triad", # Augmented chords "aug" : " augmented triad", "+" : " augmented triad", "7#5" : " augmented minor seventh", "M7+5" : " augmented minor seventh", "M7+" : " augmented major seventh", "m7+" : " augmented minor seventh", "7+" : " augmented major seventh", # Suspended chords "sus47" :" suspended seventh", "sus4" :" suspended fourth triad", "sus2" :" suspended second triad", "sus" :" suspended fourth triad", "11" :" eleventh", "sus4b9" :" suspended fourth ninth", "susb9" :" suspended fourth ninth", # Sevenths "m7" :" minor seventh", "M7" :" major seventh", "dom7" :" dominant seventh", "7" :" dominant seventh", "m7b5" :" half diminished seventh", "dim7" :" diminished seventh", "m/M7" :" minor/major seventh", "mM7" :" minor/major seventh", # Sixths "m6" : " minor sixth", "M6" : " major sixth", "6" : " major sixth", "6/7" : " dominant sixth", "67": " dominant sixth", "6/9" :" sixth ninth", "69" : " sixth ninth", # Ninths "9" : " dominant ninth", "7b9" : " dominant flat ninth", "7#9" :" dominant sharp ninth", "M9" :" major ninth", "m9" :" minor ninth", # Elevenths "7#11" :" lydian dominant seventh", "m11" :" minor eleventh", # Thirteenths "M13" :" major thirteenth", "m13" :" minor thirteenth", "13" :" dominant thirteenth", # Altered Chords "7b5" :" dominant flat five", # Special "hendrix" :" hendrix chord", "7b12" :" hendrix chord", "5" :" perfect fifth", } #=================================================================== # Triads #=================================================================== # diatonic def triad(note, key): """Returns the triad on note in key as a list. Example: {{{ >>> triad("E", "C") ["E", "G", "B"] >>> triad("E", "B") ["E", "G#", "B"] }}}""" return [note, intervals.third(note, key), intervals.fifth(note, key)] def triads(key): """Returns all the triads in key. Implemented using a cache.""" if _triads_cache.has_key(key): return _triads_cache[key] res = map(lambda x: triad(x, key), diatonic.get_notes(key)) _triads_cache[key] = res return res # absolute def major_triad(note): """Builds a major triad on note. Example: {{{ >>> major_triad("C") ["C", "E", "G"] }}}""" return [note, intervals.major_third(note), intervals.perfect_fifth(note)] def minor_triad(note): """Builds a minor triad on note. Example: {{{ >>> minor_triad("C") ["C", "Eb", "G"] }}}""" return [note, intervals.minor_third(note), intervals.perfect_fifth(note)] def diminished_triad(note): """Builds a diminished triad on note. Example: {{{ >>> diminished_triad("C") ["C", "Eb", "Gb"] }}}""" return [note, intervals.minor_third(note), intervals.minor_fifth(note)] def augmented_triad(note): """Builds an augmented triad on note. Example: {{{ >>> augmented_triad("C") ["C", "E", "G#"] }}}""" return [note, intervals.major_third(note),\ notes.augment(intervals.major_fifth(note))] #=================================================================== # Sevenths #=================================================================== # diatonic def seventh(note, key): """Returns the seventh chord on note in key. Example: {{{ >>> seventh("C", "C") ["C", "E", "G", "B"] }}}""" return triad(note, key) + [intervals.seventh(note, key)] def sevenths(key): """Returns all the sevenths chords in key in a list""" if _sevenths_cache.has_key(key): return _sevenths_cache[key] res = map(lambda x: seventh(x, key), diatonic.get_notes(key)) _sevenths_cache[key] = res return res #absolute def major_seventh(note): """Builds a major seventh on note. Example: {{{ >>> major_seventh("C") ["C", "E", "G", "B"] }}}""" return major_triad(note) + [intervals.major_seventh(note)] def minor_seventh(note): """Builds a minor seventh on note. Example: {{{ >>> minor_seventh("C") ["C", "Eb", "G", "Bb"] }}}""" return minor_triad(note) + [intervals.minor_seventh(note)] def dominant_seventh(note): """Builds a dominant seventh on note. Example: {{{ >>> dominant_seventh("C") ["C", "E", "G", "Bb"] }}}""" return major_triad(note) + [intervals.minor_seventh(note)] def half_diminished_seventh(note): """Builds a half diminished seventh (=minor seventh flat five) \ chord on note. Example: {{{ >>> half_diminished_seventh("C") ["C", "Eb", "Gb", "Bb"] }}}""" return diminished_triad(note) + [intervals.minor_seventh(note)] def minor_seventh_flat_five(note): """See half_diminished_seventh(note) for docs""" return half_diminished_seventh(note) def diminished_seventh(note): """Builds a diminished seventh chord on note. Example: {{{ >>> diminished_seventh("C") ["C", "Eb", "Gb", "Bbb"] }}}""" return diminished_triad(note) + [notes.diminish(\ intervals.minor_seventh(note))] def