Theres 256 notes in just the beginning part. Also the section is titled something like They're Hammer-Ons, so yeah, H-O. Just hold the green also while pressing the other colors and strum, but not too fast or else youll lose very quick.
PKMN Diamond Wi-Fi stuff:
Name:Robert (or w/e you like) NEW FC: 5370 - 1644 - 1978