I am new to Saxophone and music in general.
We've been discussing the tuners applications on iOS and its pitch standards. All the applications I used had A4 = 440 Hz, but the tutor claims C4 to be 440 Hz and he showed me some-setting on Yamaha PSR-910 keyboard to support this claim.
I am a bit confused, what the one I shall consider and set my tuners to it?
C4 as 440Hz (1) seems highly unlikely. Tuning standards have changed a lot over the years but it is fairly fixed today (outside period ensembles). The saxophone is a relatively new instrument and won't appear in these period ensembles (unless it is imitating an unavailable obsolete instrument).
There is a complication with the saxophone which is that it is a transposing instrument. This means that when you play a specific written note, e.g. middle C, you actually get another note. Which other note depends on the particular saxophone.
In the following cases, suppose that the player sees a written middle C.
Soprano - This is pitched in Bb which means that it actually plays a Bb. In this case, the one just below middle C. A major second below.
Alto - This is pitched in Eb so it actually plays an Eb; the one below middle C. A major sixth below below the written note.
Tenor - Also pitched in Bb but it plays an octave lower than the soprano. An octave and a major second below the written note.
Baritone - Also pitched in Eb but it plays an octave lower than the alto. An octave and a major sixth below below the written note.
An advantage is that a player can swap between instruments in the family and use the same fingerings for the same written note even though the note produced will differ.
A disadvantage is the composer, arranger, or conductor must adjust. Suppose that there is also a piano and its part is written in F then the parts for the soprano and tenor saxophones will need to written in G and the parts for the alto and baritone will need to be written in D. Alternatively, the player has to transpose while reading. This is a skill that players of transposing instruments often develop.
Back to tuning. Suppose that you are tuning against a piano or oboe playing A4, the soprano and the alto saxophone will need to play a B (not necessarily B4) and the alto and baritone will need to play an F#.
This still does not explain the C4 = 440Hz.
We could look at the clarinet. There are a few common versions.
Bb which like the soprano plays a second below like the soprano saxophone. This is the most common clarinet especially outside classical music.
A which plays a minor third below unlike any common saxophone. It will need to play a C to tune against the piano playing an A. This version is not common outside classical music.
Eb which plays a minor third above the written note. This is also rare outside classical music.
Bass clarinet, usually in Bb playing an octave and a second below like the tenor saxophone.
Addition:
So, if a clarinet in A plays a written C then it should produce an A and hence, by modern standards, 440Hz. However, to get an A4, it would need to play C5.
No common saxophone is pitched in A so it is it hard to see why any of them playing a C would produce 440Hz.
The only other instrument pitched in A that I can think of is the oboe d'amore. It is not very common in classical music and, as far as I know, unknown outside classical music.
(1) Normally Hz for Hertz. I was puzzled at first by your HZ. Scientists can be fussy and the case of units is significant and can make a big difference.
Claiming C4 to be 440Hz is wrong.
The international pitch standard is A4 440Hz. Some orchestras, particularly in Europe, tune higher (up to 445Hz).
Note: Baroque music is often performed at 415Hz (which is very close to a semitone below standard), but that's not going to be at all relevant for a saxophone player
I think what may have happened is that your teacher got it backwards: A (which has one octave at 440 Hz, as already established) on the alto and baritone saxophones sounds like concert pitch C. So they may have been thinking that C on these saxophones is A in concert pitch.
You could say your teacher...transposed the notes.
Written C is Concert pitch A - 440Hz - for a transposing instrument 'in A'. There's a 'Clarinet in A'. Can't think of anything else in general use that uses that transposition. Certainly not a sax.
So either you or your teacher has got muddled.
A=440 is conventional, although it can be moved around. C however is never ever going to be 440Hz: could you imagine any acoustic instrument detuned from its manufactured pitch by an entire minor third? Of course, you can tune to C on a tuner whose A is set to 440Hz (because some will allow you to tune A to different frequency from 440: A=432 and A=442 appear often enough). More likely, this is the option you saw on the keyboard. It sounds like your tutor is misunderstanding something, or that piano does actually allow you to tune any note to an arbitrary frequency, which makes it a poor point of reference.
