Composed and performed by Ronan Courty, this piece for solo double bass slows down the layers of time by invoking an invented age-old music, somewhere between imaginary folklore and early music. Acoustically produced, the violent and obsessive friction of the bow on the string gradually reveals hovering layers of harmonics that extend the suspension of the moment while evoking a kind of electronically produced ambient sound; the illusion created by the emergence of sustained tones is particularly effective in reverberant spaces (chapel, church, museum, forest, under a bridge ...), making this piece a contemplative and mineral moment.

This relationship between acoustic and electronic elements is dissected on the record, where side B explores the parallel dimensions generated by side A, two facets that are very present in Ronan Courty's work: "Playing Synesthesia is, for me, an intense and spiritually precious moment because it differs from my usual instrumental vocabulary less aesthetic, more raw and hypnotic".