No less an authority than Robin Eubanks thinks modern trombonists owe J.J. Johnson a share of every dollar they've ever made. J.J. was the guy who proved that the trombone's inherent limitations could be overcome and adapted to the language and tempos of post-swing era jazz. He made it possible for everyone after him to actually earn a living with this thing.
J.J. didn't just play fast. For me, he's always been an unreachable goal of apparent effortlessness and perfect intonation at any speed. From a just playing the trombone standpoint, the thing about J.J. is that it all sounds so deceptively easy. In a nutshell, he's had a bigger influence on the way his instrument is played than any other musician on any other instrument.