"...sorry to bother you but when i sat down on my laptop i tried using the jazz scale on the sheet (i'm pretty sure it was the D one) and i didn't get a jazzy sound at all.. you see, it's been so long since i started to want to learn how to improvise jazz and i could never find how online and i was wondering if maybe i'm doing something wrong? or maybe i'm misunderstanding the scale or something...but anyway, I was wondering what you use to improvise jazz, for example if someone told you to play jazz on the spot on the piano what would you do?"
It's a great question, I used to wonder the exact same thing years ago.
The "jazz" scale the author refers to is D Dorian. This scale has the notes D E F G A B C - in other words, it contains all the white notes on the piano, but starts from the note D.
This scale is characterised as having a "jazzy, minor" sound. But if you try to play it, it may not sound like jazz at all.
Let's answer two important questions:
1. What does it mean to sound "jazzy"?
2. Is there a scale which sounds like "jazz"?
To answer the first question:
The sound of "jazz" can be broken down into the following elements:
1. The rhythm. This is typically swinging 1/8 note lines in classic jazz, or complex odd-metre rhythms in modern jazz.
2. The harmony. Jazz mostly contains harmonically rich chords such as Dm9, G13b9, and Cmaj7#11 to name a few. If you hear chords like this, then it will straight away sound like jazz.
3. The melodies. Jazz uses a combination of chord tones, scale tones and non-scale tones to achieve its "jazziness" for lack of a better word.
Chord tones = notes in the chord
Scale tones = notes in the scale (these can be chord tones or colour tones, which are notes in the scale which aren't in the chord, such as 6, 9, 11 and 13)
Non-scale tones = notes not in the scale (and therefore not in the chord either)
Let's forget about the rhythm and the harmony for a moment. If someone were to play single note lines on the piano, with a straight rhythm, how could it sound like jazz? It would be due to the note choice alone.
Here's an example of a melodic line I created, in an attempt to make a melody sound like "jazz" without using any harmonic or rhythmic elements. This would sound a LOT more like jazz if I added those elements as well, but the exercise was just to see if it would sound like "jazz" with nothing but a stream of even midi notes, without even any dynamics. Does it sound like jazz to you? Or at the very least, does it sound "jazzy"?
OK, so it does sound "jazzy" to you, then why is this? Because of the use of idiomatic arpeggios, chord tones and passing tones. I had a chord sequence in mind:
||Dm7 |Bb7 A7b9 | Dm7 | Em7b5 A7 | Dm ||
This chord sequence, or a variation of it, is fairly common in jazz. The melodic line I created spells out these chords using a combination of chord tones, colour tones (such as 2nds, 4ths and 6ths, also known as 9ths, 11ths and 13ths) and chromatic passing tones, which are "in-between" notes. For example, if a melody goes from the note C to the note D, you could put the chromatic passing note C# in between and this would link them up and sound a tiny bit jazzy! I think this is the main source of the "jazzy" sound.
To get back to question 2: Is there a scale which sounds like jazz? The quick answer is no. The jazz sound comes from using scales in combination with arpeggios and non-scale tones.
However, there are a set of scales called Bebop Scales, which introduce passing notes into the usual 7-note diatonic scale.
For example, the G Bebop Dominant Scale goes like this:
G A B C D E F F#
The last note, F#, is a passing note between F and G. Without the F#, the scale would be the G Mixolydian Scale. Try playing it with and without the F#, it should definitely sound jazzier with the F# in it!
Here's another one to try: D Bebop Dorian Scale:
D E F F# G A B C
This one also has an F# added (otherwise it would be just a D Dorian scale). It should sound more jazz-like with the F# added.
Years ago when I first started playing, me and my friend Rory who also played guitar used to mess around and try to play jazz even though we knew nothing. Our first attempts consisted of both improvising on whole-tone scales such as C D E F# G# A# and making up random chords using that scale. Of course, it sounded horrible! Nothing like jazz. It took years and years to learn HOW to make the music sound the way we heard it on the records. It's a language of its own with nuances and vocabulary. Of course, the length of time it takes to learn depends on how far you want to travel into Jazzland. If you only want to visit a couple of towns, you only need enough vocabulary to order some food and buy a train ticket. You could be there in a couple of months! If you want to go and live and work there permanently then you have to keep studying until you are fluent.