You don't use a pokeflute, you talk to the guy in the radio tower in Lavender town and he gives you a special item for your pokegear. Return to snorlax and find the radio station playing Pokemon lullabies. When you press A he will wake up and you will have a chance to catch him.
to use the flute in heart gold you must have a radio go near a snorelax and use the styalus to find the station that the poke flute is on you can not use it in jahoto though but in kanto you can.
at the kanto radio tower
Play poke flute on Radio
you already have your flute its the pokegear take the button with your stylus up to the top it get poke flute theme
You will have to move that circle thing to the very top of the radio, then it will say poke flute at the top.
there is no pokeflute in heart gold. to wake up snorlax use the pokeflute channel on the radio
Use the poke flute from where the Director is standing and he will run away.
ask the little children they know you want them
To get the pokeflute in Heartgold and Soulsilver, you must go in the Kanto region and must be able to use the radio in the Pokegear in Kanto and when you use the radio, put it all the way on top.
Move the dot on the radio to te middle line, and go up until it says Poke Flute.
Give them a Bitter berry, play the poke flute,or give them an awakening
The Poke Flute is a radio station you can get after you receive the EXPN Card from the Kanto Radio Station in Lavender Town.To access the Poke Flute station, go to your radio and move the receiver icon to the top middle area.to get the red flute go to the lake of rage and to the west