Re: my Alto Sax plays half step flat
a good (and VERY necessary) place to start is to take the mouthpiece by itself (not attatched to the horn), blow it, and see what note you're producing....it should produce one of the following pitches:
Soprano saxophone: concert c3
Alto saxophone: concert a2
Tenor saxophone: concert g2
Baritone saxophone: concert d2
if it doesn't, that's at least part of your problem....you cannot reasonably expect the horn to play in tune if you're giving it the wrong input!