Yamaha GC71 The GC71 was developed to meet the demands of the greatest classical guitarist of the 20th century. Pleased with its extended bass response and greater projection we were thrilled when the maestro showed complete satisfaction in this instrument as with all GC series guitars, only materials of the highest quality are destined for use in crafting the GC71. It's solid spruce top, solid rosewood back and sides are finished with an all natural shellac, hand applied in the traditional fashion, that improves the instrument's appearance and tone as it ages.