00001 #include "MusimatChapter9.h" 00002 MusimatChapter9Section(C090400) { 00003 Print("*** 9.4 Program for Guido's Method ***"); 00004 /***************************************************************************** 00005 00006 9.4 Program for Guido's Method 00007 00008 With the Musimat programming language we can program a version of Guido's method. 00009 First, we transform Guido's vowel sequences to pitches by defining 00010 the PitchList guidoPitches, below. This lists the available pitches in 00011 the vocal gamut of his day. 00012 *****************************************************************************/ 00013 para1(); // Step into this function to continue. 00014 para2(); // Step into this function to continue. 00015 } 00016 00017 PitchList guidoPitches(G3,A3,B3,C4,D4,E4,F4,G4,A4,B4,C5,D5,E5,F5,G5); 00018 00019 Static Void para1() { 00020 /***************************************************************************** 00021 See "Musimathics" section B.2.1 for a description of PitchList. 00022 Then we need a source of judgment for which of Guido's three vowel sequences 00023 should be chosen. We'll use the integer Random( ) method to generate random values. 00024 Combining these, we obtain the program for Guido's method. Here is the 00025 version from Musimathics: 00026 *****************************************************************************/ 00027 } 00028 00029 PitchList guido1(String text) { 00030 PitchList G; //place to put the mel ody 00031 Integer k = 0; //indexes G 00032 Integer offset; //indexes guidoPitches[ ] 00033 //evaluate one character of the text at a time 00034 For (Integer i = 0; i < Length(text); i = i + 1) { 00035 Character c = text[ i ]; //get a character of the text 00036 If ( c == 'a' ) { offset = 0; } 00037 Else If ( c == 'e' ) { offset = 1; } 00038 Else If ( c == 'i' ) { offset = 2; } 00039 Else If ( c == 'o' ) { offset = 3; } 00040 Else If ( c == 'u' ) { offset = 4; } 00041 Else { offset = -1; } //the character is not a vowel 00042 If ( offset != -1 ) { //if the character is a vowel. . . 00043 Integer R = Random( 0, 2 ); //returns 0, 1, or 2 00044 Integer n = ( 5 * R ) + offset; 00045 G[ k ] = guidoPitches[ n ]; 00046 k = k + 1; 00047 } 00048 } 00049 Return( G ); //return the list of pitches composed 00050 } 00051 00052 /***************************************************************************** 00053 As an alternative to lots of If/Else statements, we can instead use the 00054 more compact Switch statement. Here's an alternative definition of function guido() 00055 using the more efficient switch statement. We'll add support for upper Case as well. 00056 *****************************************************************************/ 00057 PitchList guido(String text) { 00058 PitchList G; //place to put the mel ody 00059 Integer k = 0; //indexes G 00060 Integer offset; //indexes guidoPitches[ ] 00061 //evaluate one character of the text at a time 00062 For (Integer i = 0; i < Length(text); i = i + 1) { 00063 Character c = text[ i ]; //get a character of the text 00064 Switch ( c ) { 00065 Case 'a': Case 'A': offset = 0; Break; 00066 Case 'e': Case 'E': offset = 1; Break; 00067 Case 'i': Case 'I': offset = 2; Break; 00068 Case 'o': Case 'O': offset = 3; Break; 00069 Case 'u': Case 'U': offset = 4; Break; 00070 Default: offset = -1; Break; //the character is not a vowel 00071 } 00072 If ( offset != -1 ) { //if the character is a vowel. . . 00073 Integer R = Random( 0, 2 ); //returns 0, 1, or 2 00074 Integer n = ( 5 * R ) + offset; 00075 G[ k ] = guidoPitches[ n ]; 00076 k = k + 1; 00077 } 00078 } 00079 Return( G ); //return the list of pitches composed 00080 } 00081 00082 00083 Static Void para2() { 00084 /***************************************************************************** 00085 The program indexes one Character at a time of text. 00086 If Character c is a vowel, it calculates offset based on which vowel it is. 00087 If it is not a vowel, the program sets offset to -1 so that the final step is skipped. 00088 If it is a vowel, the program chooses a random number 0, 1, or 2, corresponding to the 00089 three possible outcomes for each vowel. This is multiplied by 5, corresponding to the 00090 number of vowels, and added to offset to arrive at the index of the selected element in 00091 the list of guidoPitches. The selected Character from that list is then stored in PitchList G. 00092 The method is repeated until text is exhausted. PitchList G then contains the list of pitches 00093 composed for this text. As its final action, the PitchList G is returned to the calling program. 00094 To invoke the function guido(), we need a Latin text. I'll use the first phrase of the text 00095 Guido used to name the solfeggio syllables, the medieval hymn Sanctus Joharines (St. John). 00096 This program fragment prints the pitches for a plain chant melody based on the text: 00097 *****************************************************************************/ 00098 00099 Print("*** Guidonian melody for the text: Ut queant laxis resonare ***"); 00100 Print(guido("Ut queant laxis resonare")); 00101 00102 /***************************************************************************** 00103 An example result of this method is shown in "Musimathics" V1, figure 9.3. 00104 *****************************************************************************/ 00105 } 00106 00108 /* $Revision: 1.3 $ $Date: 2006/09/05 08:02:45 $ $Author: dgl $ $Name: $ $Id: C090400.cpp,v 1.3 2006/09/05 08:02:45 dgl Exp $ */ 00109 // The Musimat Tutorial � 2006 Gareth Loy 00110 // Derived from Chapter 9 and Appendix B of "Musimathics Vol. 1" � 2006 Gareth Loy 00111 // and published exclusively by The MIT Press. 00112 // This program is released WITHOUT ANY WARRANTY; without even the implied 00113 // warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 00114 // For information on usage and redistribution, and for a DISCLAIMER OF ALL 00115 // WARRANTIES, see the file, "LICENSE.txt," in this distribution. 00116 // "Musimathics" is available here: http://mitpress.mit.edu/catalog/item/default.asp?ttype=2&tid=10916 00117 // Gareth Loy's Musimathics website: http://www.musimathics.com/ 00118 // The Musimat website: http://www.musimat.com/ 00119 // This program is released under the terms of the GNU General Public License 00120 // available here: http://www.gnu.org/licenses/gpl.txt
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