Author Paul Tingen suggests Miles Davis was fundamentally playing the blues with his sense of tight, precise rhythm and how he squeezed sound out of few notes (like a blues guitarist compared to say John Coltrane's sheets of sound). Napster has an explicit example, Red China Blues, that features Davis as well as a blues harmonica player.
He also points out that modernist Davis, unlike romanticist Louis Armstrong, played the trumpet without vibrato. He also suggests Davis doesn't sound dated because he both included and transcended his influences. As evidence, Miles' surprising take in 1950 on Dixieland music:
I don't like to hear someone put down Dixieland. Those people who say there's no music but bop are just stupid; it just shows how much they don't know.
Get up with it!