How do you get the Pokemon flute song soul silver?

You can't actually "get" the Pokémon Flute song in SoulSilver. There's no item called a Pokémon Flute, and the song itself isn't a separate item or file you can obtain.

However, you can access the song through these methods:

* Playing the Flute: The melody itself is played by using the Flute item. You get this item from Mr. Pokémon in Ecruteak City after solving the Bell Tower puzzle. The Flute is used to summon Entei, Raikou, and Suicune to their respective locations.

* Hearing the song: You can hear the song during certain events, such as when you use the Flute to call the Legendary Beasts.

So, while you can't obtain the song as a separate entity, you can experience it by using the Flute or by encountering certain events in the game.