Sim, se você admitir algumas instruções para transposição - incomum, mas não desconhecido.
Você pode então interpretar uma peça como Choon , que é Turing-complete. O intérprete é a memória: eles devem lembrar o número de notas pelas quais a peça está sendo transposta e todas as notas tocadas até o momento. Obviamente, é viável apenas para um computador ou talvez um savant.
Do manual do Choon:
There are three transposition instructions, up (
+), down (
-) and cancel (
.). A transposition instruction transposes all subsequent notes played by the amount of the last note played. The cancel instruction (
.) sets the transposition back to zero.
Transpositions are cumulative, so the Choon code to transpose future notes up by 2 is
b+, and by 4 would be
b++. Also, the value used is the value of the previous note after transpositions have been applied, so
b+b+transposes future notes up by 6, not by 4.
The John Cage instruction (
%) causes a one note silence in the output stream. The transposition value of a John Cage is zero -
%+are no-ops (except that a single silence is added to the output).
The Repeat Bars instructions (
:||) enclose a loop. The loop will execute the number of times indicated by the most recent note played before the
||:was encountered. A zero or negative value will mean Choon will immediately jump to start playing from the matching
:||. A John Cage means repeat forever -
%||::||is an infinite loop.
The Tuning Fork instruction
~provides a way to break out of loops. If a tuning fork is encountered in a loop, and the last note played was a note of value
A, then Choon will immediately jump to start playing from after the next
:||instruction. If there is no further
~has been used outside any repeat bars), then the performance will immediately terminate.
Markers provide marvellous programming convenience. A marker is a lower case letter or word that remembers a point in the output stream. Referring to a marker (see below) will cause the note played after the Marker occurred to be played again. Note that transpositions will affect this newly played note.
Where two or more markers occur sequentially, or a marker follows a play-from-marker instruction, they must be seperated by whitespace.
Play From Output
The Play From Output instruction (
=) allows you to play again notes that have already been played in the output stream. You can refer to the notes by number - the 5th note played since the program began would be
=5, by relative number - the 3rd most recent note played would be
=-3or by marker - the note played after marker
It is a common idiom to re-use a marker and immediately then refer to it, like this:
x=x. This is akin to saying
x=x+yin a conventional programming language (where
yrepresents the currently effective transposition value).
Um John Cage é apenas um descanso , um Tuning Fork é (aproximadamente) dal segno, e um marcador é um segno. Suponho que o diapasão poderia ser tocado por um artista a quem o ator primário responde, mas o princípio é o mesmo.