I'm on Primal as well have have been queuing towers quite a bit. It usually best during NA primetime, though I've gotten some random pops in the middle of the afternoon also. I queue English only and I'll check the queues and then go with whatever job looks like it'll make it pop faster. I don't think I've ever seen the queues completely empty....
I think it would be nice if they made some sort of towers roulette / weekly quest with relevant rewards to increase interest or make it so at least one music 100% drop (or maybe both). I don't think I'd mind the drop rate if the queues were faster, and since the queues suck it'd be nice if there were a guaranteed something to roll on at the end. I don't need it to be faceroll easy to get the drops, just.... a little bit more likely...