|Acoustics of the saxophone|
Bb soprano saxophone
Notes are the written pitch.
This is the seventh note in the altissimo or very high range. It is not a member of a simple register: although technically it plays at the sixth impedance peak, few saxophonists (except those discerning ones who have seen this site) would be aware of that. Rather, it is just a cross fingered note whose operating peak falls above the cut-off frequency and so cannot readily be described in terms of an effective length.
The weakness of this peak (due to the relatively large cone angle of the saxophone) explains why notes in this range are hard to play and require the player to assist the weak impedance peak of the bore with a strong impedance peak of the vocal tract. See this page for an explanation and some interesting results.
Sound spectrum of a Bb soprano saxophone played using fingering for C#7.
For more explanation, see Introduction to saxophone acoustics.
You can hear C#7 played.