Instructions
Start the game as normal; the story takes you through the city of Midgar, eventually depositing you outside its gates after a motorbike chase. You now have access to the World Map and are able to move freely between towns. Your first stop is the town of Kalm, northeast of Midgar.
Allow the action to unfold in Kalm. A lengthy flashback scene ensues inside the town's inn as Cloud tells the other characters of his experiences in Nibelheim as a Shinra soldier. The game switches to the past as Cloud, unrecognizable at first in Shinra uniform, rides in the back of an army transport vehicle with a young Sephiroth.
Follow the story -- the transport vehicle is attacked by a dragon and the game switches to battle mode as Cloud and Sephiroth fight of the attack. You control a young, and frankly useless Cloud, while the computer controls a vastly more powerful Sephiroth character. It doesn't matter if you die at this point in the game; Sephiroth always wins on your behalf. This is the first opportunity to play with Sephiroth on your side.
Continue to follow the action. The story moves into the town of Nibelheim. Explore the town and play the piano upstairs in Tifa's house. When Tifa asks you about the piano, tell her you "jammed on the piano;" this unlocks the Elemental material on disc two when you next get a chance to play Tifa's piano. Speak with Sephiroth at the town's inn and sleep. The next day you and Sephiroth battle your way to the town's Mako reactor, fighting more enemies. This is your second and final chance to play with Sephiroth on your side. The flashback ends inside the Nibelheim reactor and the game returns to the present.