Classical articulation strives to be as unobtrusive as possible creating a clean start to a note and enabling speed and facility. Ways to think of it include touching the tongue to the tip of the reed and taking the tongue off the reed rather than putting it on. While correctly articulating, the air stream should be supported and steady, the tongue should move only a tiny amount and the jaw should not move at all. When articulating the start of a phrase, be careful that the note is started with the breathing apparatus not the tongue and that the tongue only adds clarity to the attack. To practice this, think about the note before you play, inhale, set your embouchure, imagine the start and then begin with the tiniest touch from the tongue. If a breathy ‘fffwwwaa’ noise pre-empts the note, then air support and voicing were not correctly aligned at the beginning. If a ‘thwack’ noise is made, then too much tongue was used.
As if often the case, tiny indiscrepencies in embouchure and tongue movement can be revealed by playing on just the mouthpiece. Practice holding a concert A then articulating without changing the note. If the note splits or varies in pitch you are probably moving either your jaw or too much of your tongue, i.e. the back part. Practice making a single clear articulation without distorting the pitch. Once that is secure, try speeding up your articulation and playing bursts followed by a continuous concert A.
It is sometimes said to use the tip of the tongue to articulate but usually classical saxophonists articulate a little further back on the tongue depending on how physically large the tongue is. To get accustomed to which part of the tongue is most efficient for you to articulate try playing a normal note then approaching the tongue as close as possible to the reed without actually touching it. Of course the tongue will touch the reed and this is ok but try to focus on holding it just a hair away from where you would articulate. This may be higher in the mouth that you would usually hold it for a long note for the sake of tone colour but when tonguing a fast passage it is useful to have that mental reference.
Only by tonguing efficiently and lightly can a saxophonist tongue quickly. Therefore, learning to tongue quickly can be a way to learn to tongue efficiently in all circumstances. Practice the following articulation patterns with a metronome on a variety of notes across the register challenging yourself to increase speed. Around crotchet = 120 is the minimum professional speed of tonguing.
These exercises are good ones to practice on just the gooseneck while at the television or computer as there they will become instinctive and second nature. Once you have practiced these try synchronising tonguing and fingering by practicing scale segments: