This is simply a compilation of Evans's Riverside period, his first albums as a leader produced with Orrin Keepnews. It is a valuable period of his development, as he is already playing with people like Paul Motian and had already written "Waltz for Debbie."
Keepnews was a great impetus for this crucial period of jazz, recording Evans and Monk, among many others. I listened to some video podcasts of Keepnews a few years back, and then acquired a lot of the records he was talking about. I never regretted that.