I have recently discovered that my tilinko in C works very well played along with a blues guitarist doing stuff in C, with or without harmonica. It took me a long time to pick that tilinko out of a rack of dozens of them - I wanted one with an accurately tuned fundamental and as many harmonics as possible. I am presumably blowing to avoid harmonics that clash - I can only be totally intuitive about it, this is a theory-proof instrument.