How much of jazz tunes are improvised?

[GianGian]

I mean, when I listen to something like this http://www.youtube.com/watch?v=TU_Rx...eature=related
or Take Five performances by Miles Davis, how much of it is improvised and how much of it is composed?

[TheBasicBassist]

Well the Head or Melody is the part that is composed. Other than that, typically, the performers solos are improvised. Jazz has a handful of recycled changes that can be rewritten in different keys and the like those would be called standards; tunes like "I Got Rhythm" based on Rhythm Changes or "Donna Lee" based on Indiana being two common examples. Jazz musicians will practice standards for hours though, in every key so soloing over a tune becomes simpler and more second nature when thrown in near any circumstance. Although, it's not unheard of for solos to be 'written' beforehand. Hope this helps.

- John

[GianGian]

Originally Posted by TheBasicBassist

Well the Head or Melody is the part that is composed. Other than that, typically, the performers solos are improvised. Jazz has a handful of recycled changes that can be rewritten in different keys and the like those would be called standards; tunes like "I Got Rhythm" based on Rhythm Changes or "Donna Lee" based on Indiana being two common examples. Jazz musicians will practice standards for hours though, in every key so soloing over a tune becomes simpler and more second nature when thrown in near any circumstance. Although, it's not unheard of for solos to be 'written' beforehand. Hope this helps.

- John

So it is basically the start and the finish of the song right?
I imagine that the chrods progression, or whatever they solo over is also composed right?

[HaVIC5]

Depends on what kind of jazz you're talking about. If you're talking about most combo tune-form jazz, I'd say probably 98% of it, although it's hard to give a number. The only things that aren't improvised are the "head" (opening and closing melody) and a rough sketch of what the chord progression is supposed to be (I say supposed to be, because modern players go WAY beyond the literal chord progression). Everything else is "improvised" in the sense that it wasn't figured out literally beforehand, but there are always licks and patterns that players work out that can be woven together, like words into a sentence.

I liken jazz to speaking in front of a large crowd with no written script, and just a vague idea of what you're going to talk about. You're screwed if you can't react to the crowd, if you aren't confident, or think too much about what you're saying.

[GianGian]

Originally Posted by HaVIC5

Depends on what kind of jazz you're talking about. If you're talking about most combo tune-form jazz, I'd say probably 98% of it, although it's hard to give a number. The only things that aren't improvised are the "head" (opening and closing melody) and a rough sketch of what the chord progression is supposed to be (I say supposed to be, because modern players go WAY beyond the literal chord progression). Everything else is "improvised" in the sense that it wasn't figured out literally beforehand, but there are always licks and patterns that players work out that can be woven together, like words into a sentence.

I liken jazz to speaking in front of a large crowd with no written script, and just a vague idea of what you're going to talk about. You're screwed if you can't react to the crowd, if you aren't confident, or think too much about what you're saying.

Real nice. That is what I imagined. It must be awesome to play jazz!

[Jim Campbell]

big band stuff will be more structured but the soloist can do almost anything......in smaller groups there is what they call cuttin'.....a sort of friendly competition among players to outdo each others solos.....

if you sit down and listen to the great improvisors it becomes clear how good those guys were.......just being able to play a parker/trane/etc. solo is tough but when you know that they did it in real time off the top of their heads.......dang....

[Bassmickeyd]

Jazz Is
Most (standard) jazz tunes underline the melody at the beginning and end of the tune then everything in between is 'you know how the tune goes..... Play it!'. ..... It's not like classic rock and/or pop tunes that depend greatly on the structure of the cords/bass lines & riffs to deliver the musics message. ...... But all music, regardless of the taste/style is a language that needs some understanding of the message to deliver its meaning. ......
Since, life is short, every player, regardless of what instrument they play, but all well rounded bass players should try all styles of music sans/without prejudice.
Personally I think that jazz is the natural course for every committed musician/bass player because it allows the freedom that isn't found in too many other types of music.
That doesn't mean that you have to play jazz but its the only other type of music form gives you that type of versatile freedom.