I'm new to piano, I can play some stuff following the sheet music, but i'm always wondering if my fingers are on the right position, so, I'd like to know if there's like a map or a way to determine this? or people play however they feel comfortable with?
There are no hard and fast rules for this. See, everybody's got different sized fingers. There are plenty of ways to play the same thing. All you've got are just some general rules.
For the "piano lesson" book songs and SOME sheet music, there are little numbers next to the notes from 1 to 5.
They tell you which fingers to use on the note.
- 4th finger, ring finger, whatever
But this is (unfortunately) pretty rare. (Although extremely helpful) and sometimes given fingering won't work for YOUR fingers.
So you're going to have to work it out on your own most of the time. This is what you do in your first several "play through"s of a song:
Write it down (in pencil) on the sheet music !! (or in the midi sequencer - it lets you do that, right? :)
Use pencil, because you'll likely find a better way to finger it when you reach the next section or after thinkin' on it a bit (especially after a good night's sleep)
Watch the min and max range of notes for the section you're on, and figure out how you can make your fingers cover them best, with minimal hand position changes.
For chord after chord after chord type sections, you'll probably be moving hand positions. Otherwise, try to keep your hands somewhat stationary so you'll know what notes you have under your fingers easier.
If possible, try to keep your thumb or your pinky "anchoring" your hand.
Here's some more general tips from "Kreisler" of pianoworld.com's forums:
always figure fingering ONE hand at a time - or you'll drive yourself nuts.
determine fingering -BEFORE- practicing. You want your brain and fingers to remember ONE fingering, not a couple of variations swapped in and out randomly !!
- know what notes are under your fingers so you don't have to look down. That's why we have black keys so the hand can always FEEL where it is.
- for chords, scales and arpeggios try to use standard fingering
- if possible, anchor your hand via the thumb or pinky and keep your fingers on successive keys of the scale to match the sheet music so you can "feel intervals" (or whatever:)
- when extending to reach a "way out there" note, use either the fingers or else the thumb. then move it back so you always know what it's covering. Try to move either the thumb OR the fingers as a group. You don't want to have to readjust gaps between the 4 fingers.
- move your whole hand to a new position rather than really stretching your fingers, but also try to minimize hand hops.
- try to use your strongest fingers for important notes - first thumb, then index, then middle.
- try to minimize thumbs and pinkies on black notes since they're short, they'll squish the rest of your fingers up too far.
- practice thumb under (and 2nd or 3rd over the thumb) for smooth legato melodies. for very very fast melodies, you'll need to use what's CALLED thumb over, but really just means "scoot your whole hand".
- pay special attention to smooth transitions between passages of the music.
- DON'T bother with fingering the "easy" spots. Clearer is better.
- if the finger doesn't move, DON'T mark it on the 2nd note. just look back across the line.
- sometimes awkward fingering in an earlier passage "sets up" the start of the next passage
- ask your piano teacher how to do it !! ;)
I have more info on my site at http://pianocheetah.com/practice/fingering.html