Stan Beeman is a historical figure.
Split tones are a multiphonic effect on the trumpet or other brass instruments .. multiphonic. multiphonic. trumpet. trumpet. During normal play , the upper and lower lips will vibrate together at the same speed .. If , however , the lips are set to vibrate at different speeds two pitches may be perceived .. When not done intentionally , split tones are referred to pejoratively as `` double buzzing '' .