Recorded at the Galeria Monumental during the Small Format Materials II Festival, Sul is a large string-oriented ensemble led by Ernesto Rodrigues that includes percussionist Andrew Drury and double bassist Hernani Faustino, alongside Creative Sources core players, orchestrated with viola, violin, cello, double bass, classical guitar, zither, percussion and objects.

This supergroup of strings--16 musicians on violins, viola, cellos, double basses, piano, psaltery, zither, and guitar--in an intensely restrained collective improvisation recorded live at O'Culto da Ajuda, Lisbon, Portugal in 2017, as String Theory's 4th album continues their title themes from the physical universe named here for the rare metalloid "Tellurium".

A sense of both lightness and weight drawn from Portuguese viola player's Ernesto Rodrigues' 18-piece String Theory, in a large and detailed improvisation using an incredible array of string sources, including viola, harp, violin, cello, viola da gamba, double bass, classical, acoustic and 12-string guitars, mandolin, zither, harpsichord, and piano.