Without Composing_n°4[ver.2]

In the works catalogued as BWV 972–987, Bach transplanted concertos by Vivaldi and his contemporaries onto his own keyboard—preserving the musical ideas of the originals while infusing them with a rhythmic syntax of his own. In his hands, to arrange was to compose: creation took place between notes already written.

Without Composing_n°4[ver.2] draws its concept from this lineage, ceding the power of arrangement to a far more distant collaborator—cosmic rays. A custom Max/MSP system learns and holds all sixteen works in memory; a Markov chain derives from the scores the transition probabilities between notes, while each cosmic-ray particle registered by a Geiger–Müller counter is translated into computational parameters, steering the order in which musical phrases proceed in the algorithmic rendition.

Every fifteen minutes the system draws a work at random: the original is played through in full, and the algorithmic arrangement then unfolds—until the next turn comes. Sound fills the space through monitor speakers, and visitors find themselves within the passage between the original and its variations. The algorithm neither adds nor removes a single note; what changes is sequence alone—the music arriving now as an old acquaintance, now as something never heard before, unfolding endless variation within the bounds of the original score.

Alongside the sound, a projection inscribes each note generated that day in the notation of a player-piano roll—the trace of the music accumulating across the surface, a visual record of the cosmic rays that fell that day. No hand writes it, and yet each day leaves behind a score belonging to that day alone, never to return.

With no human hand to intervene or to end it, the performance plays on—never repeating, never ending. Bach rewrote Vivaldi; the machine rewrites Bach; and chance, from the depths of the cosmos, rearranges it all.

With the support of the National Culture and Arts Foundation, Taiwan.

在編號 BWV 972–987 的作品中，巴哈將韋瓦第等同代人的協奏曲移植至自己的琴鍵之上——保留原作的樂思，注入自身的節奏語法。在他手中，改編即是作曲：創作發生在既有的音符之間。

《Without Composing_n°4[ver.2]》概念源自這個系譜，並將編排的權力交予一位更遙遠的協作者——宇宙射線。客製化的 Max/MSP 系統預先學習並記憶這十六首作品，馬可夫鏈自樂譜習得音符之間的轉移機率；蓋格-穆勒計數器所偵測的宇宙射線粒子，每一次觸發都被轉譯為運算參數，牽動演算版本中樂句行進的次序。

每十五分鐘，系統隨機擇取一曲：先完整奏畢原版，繼而展開演算改編，直至下一次更迭。聲響經由監聽喇叭充盈空間，觀者置身於原曲與變奏的往返之間。演算法不增一音、不刪一符，變動的僅是先後次序——樂曲因此時而如舊識，時而似新章，在原譜的邊界之內開展出無窮的變奏。

與聲音並行，一道投影以自動演奏鋼琴譜的符號，即時記下當日生成的每一個音符——音的軌跡在畫面上徐徐累積，化為當日宇宙射線降臨的視覺記錄。無人執筆，每一天卻留下一份僅屬於那一天、不再重來的樂譜。

在無人介入與終止之下，這場演奏沒有重複，也沒有終點。巴哈改寫韋瓦第，機器改寫巴哈，而來自宇宙深處的偶然，重新排列了一切。

本作品獲臺灣國家文化藝術基金會贊助。