|Charlie Parker, one of the best up tempo players
Tongue Position, Air Support & Playing Up Tempo
Tongue position and breath support are easy enough to let slip a little especially after you've been playing for a while. Simply being aware of your air support and tongue position can have a great overall effect on your playing. For those of you who are asking what this tongue position nonsense is, I'm talking about the position of the back of your tongue in the back of your mouth. That is part of what helps focus your air and therefore affects your sound and intonation. A low tongue position results in dead and often unsupported sound as well as low intonation problems. A high tongue position focuses your air, sends it faster through the saxophone, and results in a more vibrant sound, a generally supported sound, and less work for your embouchure. Here are two examples, the first with a low tongue position and the second with a higher tongue position (forgive the reediness of the reed).
The first has unsupported sounding messy intonation, and you can even hear the extra pressure my embouchure is giving to try to compensate in the extra edge, fuzziness, and more strained sound. The second clip in contrast has a more supported in tune sound, and the sound is freer and more relaxed as my embouchure is doing less work.
A great way to train your tongue position is through doing various overtone exercises. I also suggest experimenting with different tongue positions while recording yourself and see what you can figure out. As far as air support goes, it's widely known that good air support is required for a good sound even when playing softly.
Articulation, Time & Burning
Articulation can be problematic for several reasons. A major problem can present itself when our articulation interrupts our tongue position. Interrupting tongue position interrupts the focus of the air flow and then wreaks havoc on our sound.
Here is an exercise, allegedly suggested by Joe Allard. Play a nice loud low Bb. While sustaining the note tongue the note repeatedly, but tongue it with the lightest possible articulation. You should maintain a high volume while tonguing very lightly. I have found that this exercise trains my tongue to maintain a good position while articulating. I often use this as part of my warm up, and I find my articulated playing is immediately better afterwards.
Another common problem with up tempo playing and articulation is when a player doesn't articulate much at all. The result is often not fantastic time, and playing that is less rhythmically interesting due to total lack of accents. Accents add depth to the rhythmic palette and are a significant part in the up tempo playing of guys like Bird and Cannonball. Following are two examples. The first lacks articulation and the second includes it.