Miles was one of the pioneers of the "Cool"
Bill Evans (although his meter could sometimes get bonkers) was spectacular.
When I was younger this type, Miles, Dizzy, Getz, Peterson, Kenton, Basie, Tatum was called progressive jazz.
If your tastes run towards big bands find all you can by a Canadian genius named Rob McConnell & the Boss Brass. VERY 'straight ahead' wonderful charts & playing.
Welcome to the world of jazz...REAL jazz, not that 'smooth (crap) jazz" that is so prevelant today.