My first article on playing double high C's on the clarinet dealt with the mechanics of getting out notes in that range - the fingerings, using a hard reed and taking in a lot of mouthpiece. But making music is much more than technique - in fact, the mechanics are only tools to work through in order to actually make music -- in order to inspire people. And boy, when these high notes are played right, they really can inspire! Like a singer going for it on American Idol or Pavarotti at the climax of a great aria, the audience can be moved, quite literally, to tears.
So, here are some suggestions on how to do that:
1. If you're improvising try to build up to the note. Create anticipation in the listener's ear by the melodic and rhythmic motion just prior to hitting the high note.
2. Be as expressive as possible - on the clarinet you can not only hold a double high C but you can play it with vibrato. You can also make a crescendo just before you're about to leave the note.
3. Regardless of the style of music try to hold the note as long as possible. If your music is strictly notated your pianist or conductor will wait for you. If you're improvising you obviously have much more leeway.
In this recording listen for the double high C at 1:22. All of the suggestions listed above can be heard in this very short klezmer tune: there's a wonderful sense of tension as the music builds to it's climax, the note itself is very expressive, and it's held for almost 22 seconds! The clarinetist by the way is my Dad, Harold Seletsky. He wrote this klezmer freylekh and specifically included a section where he could improvise and highlight his ability to circular breath on this extremely high note. Enjoy!