Since it is easier to select overtones by overblowing on the onset of a sound rather than on a sustained tone, tremolos of overtones are beautiful and very effective, also with the additional Flatterzunge technique.
Listen Tremolo Overblowing G-Bb
Listen Tremolo Overblowing F-C
Listen Tremolo Overblowing G-B
Listen Tremolo Flatter Overblowing G-Bb
Listen Tremolo Flatter Overblowing F-C
Listen Tremolo Flatter Overblowing G-B