You can make a lot of different sounds with this and most calls. I'm no pro for sure but I've been doing it many years and have seen what changing up calls can do. After a few hunts the coyotes will get smart to your calling, especially if you use the same call over and over. Changing it up will increase the number of successful hunts in an area.But sooner or later they get educated and won't come in at all, especially hunting in the East.
As for screwing up with the call, I do sometimes make a noise that doesn't sound like a coyote. At least not one from this planet. I usually quickly follow it up with a good call, like a bunch of yelps, barks,and short howls.