What's the Deal with C#?

The C# in the middle of the staff is notorious for having the worst tone of any note on the flute, not to mention the most out of tune. Why is this?

The shortest length of tubing on any instrument is going to be the worst sounding note; for us, this is the mid-range C# (essentially none of the pitch-changing keys are down letting the air escape out of the first hole in the flute). This results in less space for tone to resonate and amplify.

The flute is made up of 15 fundamentals, or 15 different lengths of tubing, creating pitches as you lengthen and shorten the tube (by pressing the keys down).

A fundamental is the lowest note on any length of tubing.  

I often find that adding a few extra keys helps stabilize the pitch of C#.  I will press the right hand ring and middle fingers down.  Sometimes this changes the tone quality as well though, so you should be careful when using this trick.  If you are playing in an orchestra where blending and being in tune is more important, then this is a good trick, however, if you are playing a solo, perhaps only pressing down the right hand ring finger to stabilize with.  This will change the tone quality less.