Guitar tabs are an informative guitar- favorable mode of putting riffs down, but they generally are not as much informative as sheet music. Guitar tabs frequently rely on backing tracks with some descriptions and analysis to support them. This is because they do not have key information and timing??" but if you are fortunate, the description will give you the key.

A lot of tabs advertised in magazines include the key at the top of the tab. But if you have a tab without the key, you will not be able to say what key it is in? Well, don't worry at least you have the notes, which is a great start. One method is to write down all of the notes and compare them to scales that you have in your mind. A great chance of figuring the key out will be there, if you can recognise 8 various notes but if you only have two the case may be different.

For example, if you pick out 8 tones and they are A, B, C, D, E, F and G that grants you some strong clues. The first 2 choices are the key of C and the key of a small-scale. I found this out by ordering the notes and comparing them to the notes in various scales.

Other possibilities include the various modes of the C Major scale. Such as:
A Aeolian ( same as the A minor-scale above),
F Lydian, G Mixolydian
D Dorian, E Phrygian
B Locrian

Experience is essential to figure out the modes in use. Particularly, you can check the chord that is being played as it will probably give you a clue. For example Em or Em7 would direct towards a Phrygian scale instead of standard major.

Of course you may run into some very complex scales that aren't just very simple to spot by looking at the notes, or even someone is simply "cheating" in which the song is being played chromatically or without reference to a particular scale. In short terms, the all-important thing is to have knowledge about the backing chords that will help you here.