You could do this with enough kernel hackery.

On thinking about it a bit more, you'll still have problems with the player software's use of swap while synchronising.

You'll either have to disable that (you might get away with it; only fsck actually needs it and you'll have to stub out fsck anyway), or suborn swapon to use network block device swap instead. But ISTR network block device swap doesn't really work.

That's if you want to remove the winchester completely, of course. If you don't mind having winchester noise when synchronising, you could always leave it in just for the swap partition, and suborn swapon() to spin up the drive and swapoff() to spin it down again.

Peter (word of the day is: "suborn")