Acman3, very interesting and fitting that you should mention both Max Roach and Jaco. As far as their contributions to the way their respective instruments are played and their role in an ensemble, one can say a lot of the same things about both players. They each pushed the boundaries of what was considered technically possible on their instrument well beyond what had been the norm until they come on the scene and they expanded the role of their instrument well beyond the traditional role of simply timekeepers. This goes to your question:
**** did Jaco decide not to lay back in support of Brecker, but to solo over Brecker's solo? ****
While I wouldn't say that he was soloing during Brecker's solo he was definitely, in typical fashion for him, much more active than the average bass player playing bass lines that were in response to what Brecker was playing as well as playing in a way that pushed Brecker and it was obvious Brecker was responding to; he even plays chords on the bass, something almost previously unheard of from an accompanying bass player. One could say that they were having a dialogue or a duet. On that particular performance the bass is mixed way up and the tenor is a little recessed adding to the feeling that the bass was soloing.
**** why Max Roach's use of poly rhythms helped the soloist, from a soloist point of view, it may help explain why Roach was so important to Jazz, ****
Max Roach broke many boundaries for drummers. Fantastic finesse at very fast tempos and his brush work is particularly great. He was one of the very first drummers to be comfortable playing in odd meters (3/4, 5/4, etc) as opposed to the usual Chin-ca-Chin, Chin-Chin 4/4 time that you have in the majority of jazz tunes, fast or slow. He was the first to use the drums as a melodic instrument by tuning his drum heads to specific and complimentary pitches. And, as you point out, he had an amazing ability for being able to play different rhythms at the same time with his uncanny hand and foot rhythmic independence. All of this was very new in the drum world.
As far as how all this impacts the soloist, it is obviously no secret that jazz playing is usually a collective effort by a group of musicians reacting to each other's musical contribution at any given moment. Even when a rhythm section player is relatively "passive" by sticking more closely to the traditional role of timekeeper only, there is a lot of nuance that can be brought to bear by way of a particular or unique time feel that the player plays with and this, in turn, influences how the soloist approaches the playing of a solo. This is one of the reasons why sometimes even the best soloists sound lackluster on certain recordings; the rhythm section is not happening. Conversely, when the rhythm section is really inspired the soloist is freed to reach greater heights of creativity which, in turn, adds more fuel to the rhythm section's simmer; they feed off each other. Now, consider a player like Roach who is able to bring new sounds and multi rhythms to the mix and how that will help the soloist push the creative envelope even further. Multi rhythms, while on the face of it, may seem to only add complexity to the mix, in a way actually make the rhythmic landscape simpler for a soloist by creating a situation in which the players rely on an implied pulse as opposed to obvious drum hits on primary beats (1,2,3,4). This is one of the reasons why the lowly (?) rhythm section player can be considered one of the most important jazz musicians as Roach was. Imagine Michael Jordan as a member of a college basketball team. Sure, it's fun to watch him score basket after basket; but, is it a good basketball game? I don't think so. In a team alongside other greats and its something special to watch.
**** did Jaco decide not to lay back in support of Brecker, but to solo over Brecker's solo? ****
While I wouldn't say that he was soloing during Brecker's solo he was definitely, in typical fashion for him, much more active than the average bass player playing bass lines that were in response to what Brecker was playing as well as playing in a way that pushed Brecker and it was obvious Brecker was responding to; he even plays chords on the bass, something almost previously unheard of from an accompanying bass player. One could say that they were having a dialogue or a duet. On that particular performance the bass is mixed way up and the tenor is a little recessed adding to the feeling that the bass was soloing.
**** why Max Roach's use of poly rhythms helped the soloist, from a soloist point of view, it may help explain why Roach was so important to Jazz, ****
Max Roach broke many boundaries for drummers. Fantastic finesse at very fast tempos and his brush work is particularly great. He was one of the very first drummers to be comfortable playing in odd meters (3/4, 5/4, etc) as opposed to the usual Chin-ca-Chin, Chin-Chin 4/4 time that you have in the majority of jazz tunes, fast or slow. He was the first to use the drums as a melodic instrument by tuning his drum heads to specific and complimentary pitches. And, as you point out, he had an amazing ability for being able to play different rhythms at the same time with his uncanny hand and foot rhythmic independence. All of this was very new in the drum world.
As far as how all this impacts the soloist, it is obviously no secret that jazz playing is usually a collective effort by a group of musicians reacting to each other's musical contribution at any given moment. Even when a rhythm section player is relatively "passive" by sticking more closely to the traditional role of timekeeper only, there is a lot of nuance that can be brought to bear by way of a particular or unique time feel that the player plays with and this, in turn, influences how the soloist approaches the playing of a solo. This is one of the reasons why sometimes even the best soloists sound lackluster on certain recordings; the rhythm section is not happening. Conversely, when the rhythm section is really inspired the soloist is freed to reach greater heights of creativity which, in turn, adds more fuel to the rhythm section's simmer; they feed off each other. Now, consider a player like Roach who is able to bring new sounds and multi rhythms to the mix and how that will help the soloist push the creative envelope even further. Multi rhythms, while on the face of it, may seem to only add complexity to the mix, in a way actually make the rhythmic landscape simpler for a soloist by creating a situation in which the players rely on an implied pulse as opposed to obvious drum hits on primary beats (1,2,3,4). This is one of the reasons why the lowly (?) rhythm section player can be considered one of the most important jazz musicians as Roach was. Imagine Michael Jordan as a member of a college basketball team. Sure, it's fun to watch him score basket after basket; but, is it a good basketball game? I don't think so. In a team alongside other greats and its something special to watch.