Yamaha GC1 TA3 TransAcoustic grand piano - polished ebonyIntroducing the Yamaha GC1 TA3 TransAcoustic grand piano The GC1 grand piano is perhaps the most obvious 'upgrade' from the Yamaha GB1 grand piano. At 5'3'' the instrument is larger, and this alone is enough to give the instrument more depth, especially in the lower registers. Among other refinements, the GC1 also benefits from 'duplex scaling' which is a method of bringing out a fuller tone from a piano by tuning what are known as the 'non speaking'