It is on the radio. To 'tune in' to this station drag your cursor to the top of the signal screen thingy. Hope I helped!
There is no channel silver flute, only poke'flute. Top middle line
in the kanto
you can't get the poke flute on soul silver however you can get it on the poke radio to wake the sleeping snorlax blocking entrance to diglets cave.
move the dot to the top, you should find the poke flute channel
Play Pokemon flute song
From a man in the Pokemon tower.
Wednesday (I think)
You can't really find the poke flute but its on your radio on your pokegear its a secret channel that you have to go all the way up on to get the station
you need to have a poke flute. by unknown
go into one of the poke centers (don't know which one) and ask one of the guys ask him and then he will give you a poke flute
it only plays music