These are five things I learned from him:
1) Play sustained.
Arno most important lesson is to always connect the notes. To always let the air be the basis of your phrases and to not let the fingers determine the direction of the phrase.
2) Always play a tune.
Arno taught me always find a tune in everything I play. Even in the most avant-garde pieces. I always needed to play towards a certain note, even is there was no tonality to help me point out the obvious.
3) Play in tune.
Always take care of intonation. And correct with embouchure, but if it's too much, correct with fingering. There are saxophonists who are against this way of correcting and say you should correct only with embouchure. Arno taught me to use every means necessary to play in tune.
4) Eliminate technical problems.
To be truly free one should eliminate technical problems. Firstly by studying exudes and scales. The first year in the conservatoryI almost only studied technique to take away as many technical barriers as possible. The technique that is left one can solve by finding musical solutions to technical problems.
Arno taught me to look for colours, by using vibrato and changing the sound by using the cavities in the throat and chest. He also taught me that my basic saxophone sound is not that important. What is most important is what I do with it.