absolutely right mike!
if you wan’t to learn about expression, the best place to learn it is from listening to someone singing! they don’t have to trill, glissando etc.. to express themselves, they do it all by controlling dynamics, speeding up and slowing down etc.. no gimmicks, or attention grabbing sounds emanate fron their lips.

Another thing about singers, if you watch closely their body language also expesses the feelings they exress in their singing, 2 things are happening at the same time. so you could do a similar thing while playing the sax, but be careful your body language fits the mood of the song, otherwise you can end up being comical.

but the magical thing about singing, if you listen to the singer on a record, you don’t see the body language, but your ears still convey the feelings to your mind.