Interestingly, I owned a Sigma trade guitar, unbranded. It sounded OK and I played it one night at Pete Coe's club. Still reckon that a mid range Yam had the edge though. I also had a Levin for a while. Solid Top and Brazilian rosewood back and sides. It was OK, but was soon sold on. I use a Yamaha FG 365SE bought new in 1983 nowt to beat it.