Pirastro Permanent Cello Stringssteel strings brilliant sound warm core tone short decay very quick response The A and D strings are brilliant and bright sounding, and have a core made from a single filament of high tensile steel wound with chrome steel. The G and C strings have a rope core wound with tungsten. The G and C strings provide a warm and powerful sound and have a short decay with very quick responses. The set offers exceptional tuning stability and immediate playability.