Musical dice game

Several 18th century composers such as Mozart and Haydn composed music which is performed by rolling dice to determine the sequence of measures in the music. The table below contains one of these dice-game compositions: Musikalische Würfelspiele (Musical Dice Game), Kontre-Tänze (Contra-Dance), K⁶ Anh. C30.01 (K³ Anh. 294d) by Wolfgang Mozart.

The piece is generated by rolling a pair of dice. The outcome of the dice roll is a number between 2 and 12. For each measure in the composition there is a set of 11 possible measures which are chosen by the dice roll. For example, if a 9 is rolled for the first measure of the piece, pre-composed measure #142 will be the first measure of the generated composition. If a three is rolled for the second measure, then measure #64 will be the second measure of the generated composition. You can view the individual measures in Humdrum text format or in MIDI file format in the table below.

Humdrum files:

A section ROLL: 2 3 4 5 6 7 8 9 10 11 12 A1 = 070 010 033 036 105 165 007 142 099 085 145 A2 = 014 064 001 114 150 152 081 106 068 045 097 A3 = 164 100 160 008 057 112 131 040 086 090 006 A4 = 122 012 163 035 071 015 037 069 139 158 121 A5 = 025 149 077 111 117 147 021 043 120 082 056 A6 = 153 030 156 039 052 027 125 140 092 123 067 A7 = 018 161 168 137 132 073 049 023 143 078 063 A8 = 167 011 172 044 130 102 115 089 083 058 016

B section ROLL: 2 3 4 5 6 7 8 9 10 11 12 B1 = 070 010 033 036 105 165 007 142 099 085 145 B2 = 014 064 001 114 150 152 081 106 068 045 097 B3 = 164 100 160 008 057 112 131 040 086 090 006 B4 = 122 012 163 035 071 015 037 069 139 158 121 B5 = 025 149 077 111 117 147 021 043 120 082 056 B6 = 153 030 156 039 052 027 125 140 092 123 067 B7 = 018 161 168 137 132 073 049 023 143 078 063 B8 = 167 011 172 044 130 102 115 089 083 058 016

MIDI file equivalents:

A section ROLL: 2 3 4 5 6 7 8 9 10 11 12 A1 = 070 010 033 036 105 165 007 142 099 085 145 A2 = 014 064 001 114 150 152 081 106 068 045 097 A3 = 164 100 160 008 057 112 131 040 086 090 006 A4 = 122 012 163 035 071 015 037 069 139 158 121 A5 = 025 149 077 111 117 147 021 043 120 082 056 A6 = 153 030 156 039 052 027 125 140 092 123 067 A7 = 018 161 168 137 132 073 049 023 143 078 063 A8 = 167 011 172 044 130 102 115 089 083 058 016

B section ROLL: 2 3 4 5 6 7 8 9 10 11 12 A1 = 070 010 033 036 105 165 007 142 099 085 145 A2 = 014 064 001 114 150 152 081 106 068 045 097 A3 = 164 100 160 008 057 112 131 040 086 090 006 A4 = 122 012 163 035 071 015 037 069 139 158 121 A5 = 025 149 077 111 117 147 021 043 120 082 056 A6 = 153 030 156 039 052 027 125 140 092 123 067 A7 = 018 161 168 137 132 073 049 023 143 078 063 A8 = 167 011 172 044 130 102 115 089 083 058 016

To generate a composition, you would roll the dice 16 times, and choose a measure for A1 through A8 and B1 through B8. The table below gives a list of 100 random realizations of the contra-dance. The set on the left contains the music in Humdrum format, and the set on the right contains the music as MIDI files.

Humdrum

001 002 003 004 005 006 007 008 009 010 011 012 013 014 015 016 017 018 019 020 021 022 023 024 025 026 027 028 029 030 031 032 033 034 035 036 037 038 039 040 041 042 043 044 045 046 047 048 049 050 051 052 053 054 055 056 057 058 059 060 061 062 063 064 065 066 067 068 069 070 071 072 073 074 075 076 077 078 079 080 081 082 083 084 085 086 087 088 089 090 091 092 093 094 095 096 097 098 099 100 MIDI

001 002 003 004 005 006 007 008 009 010 011 012 013 014 015 016 017 018 019 020 021 022 023 024 025 026 027 028 029 030 031 032 033 034 035 036 037 038 039 040 041 042 043 044 045 046 047 048 049 050 051 052 053 054 055 056 057 058 059 060 061 062 063 064 065 066 067 068 069 070 071 072 073 074 075 076 077 078 079 080 081 082 083 084 085 086 087 088 089 090 091 092 093 094 095 096 097 098 099 100

To combine the individual measures, use the humcat command. This command will join two or more Humdrum files into a single data stream. For example, with these two files:

file1.krn:

• • kern **kern

=122 =122 4C 8cc . 8g 4CC 8e . 8c

• - *-

file2.krn:

• • kern **kern

=161 =161 4C 16ee . 16gg . 16ee . 16cc 4D 16b . 16a . 16g . 16f#

• - *-

The command:

  humcat file1.krn file2.krn

will generate the following composite data:

• • kern **kern

=122 =122 4C 8cc . 8g 4CC 8e . 8c =161 =161 4C 16ee . 16gg . 16ee . 16cc 4D 16b . 16a . 16g . 16f#

• - *-

humcat can join any Humdrum files which contains the same number of spines and matched exclusive interpretations at the join points.

Suppose the you roll dice with this pattern: "2 5 10 6 3 8 9 9". Then, you can generate the A section of the contra-dance with the following command:

  humcat cda000.krn cda070.krn cda114.krn cda086.krn cda071.krn \
         cda149.krn cda125.krn cda023.krn cda089.krn > partA.krn

If you use the same dice rolls to generate the second section, this is the command which would be run:

  humcat cda155.krn cda157.krn cda029.krn cda019.krn cda031.krn \
         cda080.krn cda096.krn cda127.krn > partB.krn

To generate the final composition, combine partA.krn and partB.krn together:

  humcat partA.krn partA.krn partB.krn > full.krn

Exercises First, download the individual measures to your local computer. Or, alternatively go to the kernscores website and download a zip file of the source material. Click on the "Z" button on the page:

  http://kern.ccarh.org/cgi-bin/browse?l=dice/mozart

Generate an example composition by rolling some dice and using humcat to combine the individual measures into a single Humdrum file. Then convert that file to MIDI and listen to it. Repeat until bored. To generate a large number of variants, download and run this PERL script. If you do not have real dice, you can borrow my pair of virtual dice, by typing the command (BASH shell version):

NUM=$RANDOM; let "NUM %= 12"; let "NUM += 1"; echo $NUM Or a PERL language version:

       perl -e "print 2+int(rand(6))+int(rand(6))"

For example, if you roll a 7 and then an 11, then the combining command would be:

      humcat cda000.krn cda165.krn cda085.krn

Which will start the composition with these two measures:

Combine some of the measures in a non-proscribed way. For example, paste the measures together in reverse order. What does the music sound like?

Examine the musical key of each individual measure in the composition. In particular, choose a row from the A or B columns and measure the key in each measure listed on that row. For example, the key of measure 060 which is for roll 11 in the B8 column is in the key of C Major:

  keycor h://dice/mozart/cda060.krn

     The best key is: C Major

What is the pattern of musical keys for measures in a particular row? What is the pattern of keys in measures in a particular column?

Create a set of realized contradances, then identify the musical key of the dance by using the Humdrum command "key", or the Humdrum Extras command "keycor". Are all of the compositions in the same key or different keys accoring to the key program?