Simplicity is key. Bowing, shifting and rhythm depend on inhaling a resonating air, then blowing. Each note repeats at least twice in a dotted rhythm. Amos trains his ear, the left one, to feel joy as the note repeats and skips. The right ear hears only imperfection. He comes to love this imperfection, too. Spiccato sounds like frog scales in early spring; a smooth legato is a sticky toffee scale, strung between teeth and fingertips.