What is the role of a pianist in a jazz band?

[Bob]

i.e. Having a bass player present.

I can understand what the left hand is doing if there's no bass player -- The LH is playing the bass notes.  But without the bass player, what is the jazz pianist doing?  Chords and rhythm?  And little fill ins?

Even then, it's chords with both hands instead of bass note in LH and rest of the chord in RH?

[mikey6]

As in a full stage band with brass/winds?  Besides busting out a solo or filler 'licks', harmony more than anything I would think - different to the rest of the band where you cold highlight each section or switch between the groups.
The bass player takes the bass line but the pianist then has to know how to voice lh correctly - 1st inversion chords are the norm with exceptions I'm guessing.
Listen to Count Basie maybe, he normally takes the tune first before handing it off to the band.
I think that kinda makes sense...

[scottmcc]

well...it's kindof a big question, and dependent on the sub-genre of jazz to which you are referring.  in earlier jazz ("classic" jazz, new orleans jazz), the piano tended to be more of an accompanist, and was really just part of the rhythm section except for a few isolated solos.  as time went on the pianist took more of a leading role, even in large combos.  of course, for smaller combos such as piano/drums/bass the piano is the lead instrument, but that didn't emerge until much later.

the best way to answer this question is for you to watch Ken Burns' Jazz documentary, and just listen to the piano parts throughout.

[oxy60]

Alternatively you could read some of the books by Leonard Feather.

I've been wondering about this exact issue. In the blues, except for a TASTEFUL fill now and then I can't seem to find a place because everything is covered.

[venik]

Generally Piano is rhythm outside of solos. But they sometimes sing along with the melody. But really it depends on what your playing with. Think about most jazz melodies, they are pretty simple. Having 10 fingers playing 1 melody would be complex, crowded, and kind of a waste. So when the piano does play the melody, it's generally also playing the bass line or rhythm. But jazz is hard to classify like this as sometimes the rhythm is the melody, like in watermelon man kind of.