Without Composing_n°4

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 draws its concept from this lineage, ceding the power of arrangement to a far more distant collaborator—cosmic rays. A custom Max/MSP system first performs the original works in full through MIDI data; a Markov chain learns from the scores the transition probabilities between notes, while each cosmic-ray particle detected by a Geiger–Müller counter is translated into computational parameters, steering the order in which musical phrases proceed in the algorithmic rendition.

Wearing wireless headphones, visitors move back and forth between the original and its algorithmic counterpart. 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.

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》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 程式系統先以 MIDI 資料完整演奏原曲；馬可夫鏈自樂譜學習音符之間的轉移機率，而蓋格-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。

觀者戴上無線耳機，在原曲與演算版本之間往返聆聽。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。

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。