I've been playing flute for about four years now, but even with a brand new flute, I have had trouble getting any note above Eb6 (Eb above the octave) out. I know that it involves my breathing, since when I breathe fast, the flow is not straight or thin. I know that it is not because of my instrument, as my friends have been able to get E6 to A6 on it (that's as much as we've been using). Any advice would be appreciated. Almost all of the songs we're playing in Marching band class are using this range.

First, are you SURE you are fingering them correctly? Many people just assume that high notes are the same fingerings as low notes. So, I would make sure and double check that...try looking at the fingering chart in the back of a method book to be sure. After you make sure of that, make sure to use superfast air. To practice, try taking a notecard sized piece of paper and pressing it against the wall. Breathe in, and when you blow out at the paper remove your hand so that you are keeping it up with your air. If you still have problems after trying to adjust those aspects, there are some alternate fingerings to help intonation and ease of playing for the high notes. But, I always feel that it is best to get them out with original fingerings first.

The fingerings definitely get interesting. I find that sometimes the charts are also a bit off, so experiment a bit with fingerings, especially on your right hand. Some notes are suddenly a snap with that one trill key or low note(foot joint) pressed down.

I personally have no less than three fingering charts - and all three are different in the upper octave.

A good fingering chart that combines both the standard fingerings and many alternatives can be found at:

www.wfg.woodwind.org

It also has charts specifically for piccolo, alto and bass, trill fingerings, etc.