Hammer & Half-Life 2: Shuffle Songs Using Logic? Thread

Hello, I would appreciate some assistance with rigging up a logic system in Valve's Hammer Editor for Half-Life 2 that upon map entry by a player, one of 16 songs plays. (Chosen at random)

I figure it involves:
logic_auto(OnMapSpawn) -> logic_case(PickRandomShuffle) -> ambient_generic(w/ timed trigger of logic_case)

Have I missed anything? Is there a simpler way? I don't want to have to change the game library. (Binary/dll)

EDIT: How do I assign music to the music channel, so those who wish not to hear the music can pot it down in their settings?

Edited by: Sehnsucht!