I've always loved synthesized horn sounds. I think they sound wonderful, and unlike real horns you can sequence them to have very fast progressions, which sounds completely unnatural but sort of other-worldly and beautiful. The Roland ProMars has some great horn presets, but it's very easy to make these sounds from scratch too.
I recently discovered that I didn't really know what the GATE + TRIGGER Control switch on my SH-09 did. Almost ten years together and still getting aquatinted! So anyway, there is a switch on the SH-09 for envelope control. It can either be set to Gate + Trigger, just Gate or LFO. What is Gate + Trigger? What is it's dark purpose? Well, if you only have Gate selected when you hit one note, keep it held down, and then hit another note: nothing happens. If you have Gate + Trigger selected: you can keep one note held down and then hit another note to trigger the envelope (well… only a lower note, because the keyboard is low note priority). This function is particularly useful in brassy sounds, which, by the way benefit from having all the envelope controls set pretty low except for a good deal of sustain.
For more information see the SH-09 manual or Practical Synthesis for Electronic Music page 14. Or this great article from Sound on Sound: SYNTH SECRETS Part 27: Roland SH101/ARP Axxe Brass Synthesis