after you fix the power plant a person in lavender town (inside the radio tower) and he gives you it to move the snorlax (which you can catch)
Play poke flute on Radio
at the kanto radio tower
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.
ask the little children they know you want them
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
well you get a poke flute and go to the snolax wake it up and go throe the tunnel and there you are
In poke platinum you get a black poke flute from Looker the agent
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.
there is no pokeflute in heart gold. to wake up snorlax use the pokeflute channel on the radio