The Poke Flute is not an item in "Pokemon Crystal," unlike in versions Red, Blue and Yellow where it is an item needed to wake up the Pokemon Snorlax. Starting from Pokemon Game versions Gold, Silver and Crystal, the huge sleeping Snorlax is blocking the way to Diglett's Cave. To wake up the Snorlax and proceed with the game, players must use the Poke Radio and tune it to the Poke Flute station, which is the station at the highest bar on the radio.
The Snorlax is a Normal Type Pokemon with the abilities Gluttony, Immunity and Thick Fat. It is number 225 entry on the new Pokedex and is number 143 on the National Pokedex. The Pokedex entry of the Snorlax reads, "This Pokemon's stomach is so strong, even eating moldy or rotten food will not affect it." On Pokemon game versions Gold, Silver and Crystal, the Snorlax is located in Vermillion City.
On Pokemon Crystal, once the player arrives at Vermillion City after battling Pokemon trainer Janine at Fuschia City, he will need to proceed to Diglett's Cave to be able to get to Pewter City. The sleeping Snorlax that is blocking the way to Diglett's Cave is a level 50 Pokemon, which means that it already has the moves Rollout and Body Slam. After activating the Poke Flute on the radio, the player then can choose to either knock out Snorlax or capture it.