As far as I know, at least what I have listened to, Elvin's first appearances on record date back from 1957. On Sonny's Vanguard stuff, Elvin definitely is playing in that more conventional bop mode, but theres the polyrhythms forming and a circular sense of time. Back when these sides came out, was there feeling that Elvin was doing something new, or did that something really "new" hit in 1961 when he joined Trane? Personally I can hear it on those "Night at the Vanguard" dates with Newk.