Obligato strings are based on an exclusive new core material, along with advances in manufacturing techniques, resulting in the true warmth and complex overtones of gut core strings with the stability and quick response of synthetic core strings. Obligato has also demonstrated quick break in time, exceptional projection, and unusual durability. - Obligato strings have a core made from a modern synthetic multifilament fibre. - Obligato strings sound warm and full, yet have a brilliant, rich overtone spectrum and focused tone. - excellent playability and response throughout the entire dynamic range - great tone volume - excellent tuning stability - absolutely insensitive to variations in temperature and humidity Set: The standard set contains the following strings: E-goldsteel, A-aluminum, D- and G-silver.