I'm playing guitar and therefore have learnt all the major,minor and harmonic minor patterns. But while improvising I usually forget the right notes of a scale(the problem comes when switching the scale pattern). So should I learn individual notes of a scale or is there any other way to improve. Thanx
The most important thing is to be able to know and see on your guitar the intervals between each scale tone and the root note. If you're able to do this then you're independent of the key and you don't necessarily need to know the name of the note that you play, as long as you know its relation to the root of the scale.
So when you learn scale patterns make sure that you always know where the root is. Then make sure you know how all the other notes relate to the root. E.g., if you practice the natural minor scale, one thing you need to know is that it has a minor third. Then try to be able to see that minor third interval (counted from the root) everywhere on the guitar: 3 frets higher on the same string as the root, 2 frets lower on the next higher string from the root, unless the root is on the G string, then it's only one fret lower on the B string, etc. I guess you get the idea.
And finally don't forget that your ears can help you a lot. When you play intervals try to be able to hear them in your head before you play them. Try to get the sound of the scale into your head. And as soon as you know your guitar well enough to be able to produce intervals that you hear in your head, you will be completely free to play any scale or melody without slavishly sticking to learned patterns. This is a long way to go, but if you use your ears (even more) while practicing, and if you concentrate on hearing and seeing intervals of scales then I'm sure that you will progress quickly.
Following on from Matt's excellent answer, one thing I get my pupils to do is make up a phrase, say 6 or 7 notes, in a particular key, using, say, major, minor or blues. Then to be able to move it around the neck, and play it in any octave, starting on any string (dependent on the phrase, obviously), in maybe two different ways from a start note. The start note initially is a root note, then maybe an anacrusis 5th, then anything goes. Knowing where a start note is in any octave, is good, then using intervals for the other notes works well.
Being able to play any scale, from any position within that scale, and in any combination of intervals (rather than just stepwise motion up or down) is simply the very beginning and the bare minimum required to be a competent improviser (without spending decades learning how to "do it by ear only").
Understanding basic harmony, which means understanding the relationship between one key to another key (tonic key <-> dominant key, etc) will greatly help you. Yes it takes work, but it is necessary for you to truly understand what you are doing when improvising.
I have numerous friends who are musicians, and I've noticed that a lot of people don't have the time or don't want to make the time to understand music as it is: a language. Understanding fundamental theory is critical.
As far as "forgetting the right notes of a scale", time will take care of this (but of course, understanding what you are doing by studying harmony will greatly help with this).
You already know all the notes of all the scales. There are only so many notes available and the names just repeat themselves all over the fretboard. Once you memorize them you know them all. The real trick to playing guitar is figuring out which ones go where and with which other notes, when you do that successfully you make music. :)