The other day I was thinking about measuring the complexity of tabs in order to get an idea as to how "hard" to learn a particular song might be.
One straight forward approach is to count the number of symbols (i.e. the tab length). The results are presented below.
It is important to note that even though we get a first cursory measure using this technique, we are still fairly limited, as we do not take into account things like the length of the actual song (the tabs tries to reflect), the adequacy or quality of the tab (for a particular song), more generally the internal variations within a song/tab (take the same note on the same fret for example vs. high-distance movements between frets and strings), as well as the information/noise ratio within a tab and other factors.
That said, here are ...
Note: why am I not surprised to see Dream Theater leading the list? :)