The best thing you could do is get a voice coach who is an experienced musician/singer/actor and work with him or her on these problems.
They will be able to determine your vocal range and whether you are trying to hit notes you cannot. They can tell you better than anyone in here the reason why you are "flat." You can also ask your music teacher at school but it would seem to me that you need vocal training to attain your singing goals.
A vocal coach is well-versed in the correct breathing techniques you will need and will know how to teach you to breathe properly and figure out why your chest feels so tight. When it comes to that it's not normal to experience it when singing or period.
There's a significant problem here only a vocal coach or music teacher would know how to fix. Just so you know for your own self ask what your friends mean by saying it was flat? I doubt they mean tone deaf here but probably are saying there's something wrong your singing.
sportscutie13 answered Wednesday February 7 2007, 7:07 pm: I am a trumpet player and I've had similar problems in my playing, and you'd be surprised how related they are. Practice singing with a tuner, most likely you are just hearing the pitches flat in your head. Breathing exercises: A) if you want to be creative, try doing yoga. I tried it and it helped me...
B) breathe deep, long slow breaths before you practice to get the feel of your air supply
C) Think about breathing from your feet
D) Relax your shoulders, and think "suction" through your lips, you should be able to feel your lips get cold when the air passes through.
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