I've recently been practising on a piano (I usually play the guitar or the bass) to figure out what the pianist in our jazz band does and I must say I like it a lot (the heavy feel of the keys under one's fingers especially). I can comp on the tunes we play at the moment but I would like to take it a step further and learn major and melodic minor scales on the piano. I've tried figuring out a major scale (G flat it was, I think) and I used the tetrachords I know from my guitar playing and tried to work my way through the Gb scale (moving up ionian, down dorian and then up phrygian etc...) and then I thought "Wow! That worked!" and then I thought "Wow! There are 11 more keys to go and I can't just move my hand up or down like I do on the guitar!" Could a pianist please tell me how you lot go about learning all those fingerings? Should I stop thinking in terms of tetrachords and think tones? The task seems herculean!
"All those fingerings" are actually pretty consistent. (They certainly didn't look that way when I first started working on scales!) Each scale has seven different notes. All of them are fingered with some sequence of 1, 2 and 3 (thumb, index, middle) and 1, 2, 3 and 4 (ring), one of each per octave. Also, you never use your thumb on black keys.
The differences occur at the ends of the scale. Since you never use your thumb on black keys, scales that begin on a black key start the sequence somewhere in the middle.
C has no black keys, so it's the best scale to use to learn the sequence. (But also, since it has no black keys, it's one of the hardest to master, since you don't have the black keys as reference points.) In two octaves, the fingering goes like this:
Right hand: 123123412312345 Left hand: 543213214321321
This fingering is the most common, used for (I'll stick to major scales) C, G, D, A and E.
B has a black key on the 5th scale degree, so the left hand reverses the sequence, using 4 to start:
While the right hand uses the same fingering as C.
Conversely, F has a black key on the 4th scale degree, so the right hand reverses the sequence, using 4 to end:
While the left hand uses the same fingering as C.
Scales that start on black keys use a combination of 123 and 1234, starting at a different point in the sequence in such a way as to avoid having to use the thumb on a black key.
RH: 212312341231234 LH: 321432132143212
RH: 212341231234123 LH: 321432132143212
RH: 231231234123123 LH: 321432132143212
RH: 231234123123412 LH: 321432132143212
RH: 234123123412312 LH: 432132143213212
There are, of course, the harmonic and melodic minor scales as well (and the other modes, if you want to experiment with those). You can find all of the major and minor scales written out with fingerings in most exercise manuals. Here's a pdf file of the Hanon exercises. Scales start on page 50.
You should checkout Czerny etudes for piano. Although it isn't jazz, it really helps developing correct finger positions which will help with any other scale down the line. Hope it helps.
When you move your improvisations across the neck of the guitar key-independently, you lose some material: open string notes and their harmonics. Since they have particularly solid sustain and a distinct sound (and a distinct pitch as well when playing in higher positions), they are important music material. So viewing the guitar as freely transposable is limiting its possibilities, too.
That being said: you need to be at home with the notes and the keys like a speed typewriter is at home with his typewriter's key layout. The end game is thinking about notes and music, with the fingers catering for doing the execution on the keys.
Yes, that means 12 scales (actually more). If you find that disheartening, there are keyboards that are much more regular. For piano type instruments, there is the comparatively rare "Jankó keyboard" (look it up). But the only regular keyboard instrument with significant distribution I know of is the chromatic button accordion (think of a 16-string guitar tuned in minor thirds). In its five row (think of four frets) incarnation, you can design your improvisations on three rows, and then indeed you can move its "shape" to any pitch you want in a manner similar to what you do on the guitar now.
Of course, if you play the piano for its percussive sounds with individual loudness, the tight hand shapes on a button accordion keyboard (even if you have a midified version with velocity sensitivity) will not be a good match. It's a more natural controller for continuous-tone instruments.
This could be a great opportunity to expand your improvisation from scale-based to melody-based. Guitar technique encourages the former.
Yes, on keyboard there are a few scales that share the same fingering, but plenty that are individual. But it's not THAT hard. There are patterns, dictated by the positions of the black notes - in scale playing (but not chord playing) the thumb avoids the black notes. In Gb major you found the easiest scale to play on keyboard! The fingering HAS to be 2,3,4,1,2,3,1,2. The only question is WHICH of the white notes between the two black blocks you choose to put your thumb on. C major is hard. There are so many possible fingerings that you're tempted to just 'wing it' each time, instead of settling on a consistent fingering which will deliver reliable fluency.