With jazz I would say Maynard and Dock, maybe Miles.
With classical I am not who it was but I think Roger Voisin started playing his C trumpet in the orchestra. That surly influenced people. Again in Boston Charlie Schlueter had (has) a different stile and influenced a lot of players
There are a lot of players on here influencing change. A while back Manny L. was a very strong influence on here. I'm not sure he was breaking new ground but he sure had an effect on a lot of players here.
There are a lot of players that are super fantastic players but not necessarily ground breaking or reaching out influencing players.
I would also think that Herseth with his personality and strong musical playing.