The piano sound used in the beginning is from the SRX 11 expansion board, not a stock piano of the G70. I'm sure of that because he explains that the sound uses 704 samples ("sept-cents quatre échantillons") - that's the figure from the SRX 11 advertisement. A bit of a mean marketing trick to present it that way, but ok, it won't harm anyone any more

BTW: How 704 samples? Very easy: 88 keys, 4 velocity levels, separate for left and right channel. 88 * 4 * 2 = 704.