Yah Gary. I did a lot of reading on how Freddie Green got "that" sound a few years ago. When I discovered that it was the "missing" notes that made his chords stand out, it was a revelation. Likewise Eldon Shamblin with The Texas Playboys. Because I play solo most of the time, but still want that "moving bass line feel" on swingy tunes, I've done some ammending and rarely alter the chords beyond the 6th, 7th, and 9th. Almost always use the m7th though. I'll use a b5 occasionally in the bass, but only as a quick passing chord.
Rick