Well, lets get you started.
(1) play a middle C on your tpt., not too loud.
(2) While still playing the middle C, HUM a second line G. After you “balance” the volumes and “tune it up”, you will be able to hear a complete triad!
This may be a bit tricky at first, but easily done.
Clyde’s advice on how to get started with multi-phonics is excellent. A couple of additional thoughts:
1) It is always easiest to sing ABOVE the note that you are playing to get a multiphonic.
2) A large bore instrument such as a flugelhorn will amplify your singing more than a trumpet.
With that in mind, you can actually get FOUR different notes by using difference and summation tones. A difference tone is a third pitch produced as the difference between two frequencies, a summation tone is produced by the sum of two tones. So if you play an A at 220 CPS and sing an E at 330 CPS, you’ll also get a low A at 110 CPS and a C# at 550 CPS. This is why you get a complete triad if you try what Clyde recommends. If you sing another interval, you will get varying difference and summation tones. Bear in mind that the normal spectrum of human hearing is 20 CPS to 20,000 CPS. Some combinations can be really wild.
In August 1996 I played with “The Latter” during their run at the Knitting Factory. We used filters to emphasive various notes in flugelhorn multiphonics. It was fun!
Ted McIrvine ———————————————-