Middle and high grade. According to the brand website information, Tianyi Guzheng belongs to Yangzhou Tianyi National Musical Instrument Factory and is a brand in Yangzhou, China. It is one of the middle and high-grade guzheng brands, with A-grade paulownia as the bottom plate and panel, and A-grade white pine and colored wood as the frame materials, which makes the sound quality more mellow, transparent and meaningful.