Deriving from the initial, essential gesture featuring the interval of a tritone -common to all the pieces in the series- in natural harmonics, the main echo showcases the full-bodied tone and captivating range of the tenor saxophone. Between classical and jazz tenor sounds, a melodic discourse develops over various tone colors and sound production techniques. The echoes take a microtonal turn as they start reechoing the inharmonic multiphonics punctuating the phrases. As the echo finally gets more structured, it also becomes faster and creates a movement in which the repetitive rhythm becomes the very source of energy.