You said something about the 5 different positions. I've heard people talk about the 5 positions for pentatonic scale, where 1 position has a root as the lowest note you can reach, then another position has the next note in the scale as the lowest note you can reach and so on for the 5 notes of the scale or 5 positions. If you can do that then all 5 positions mesh into 1 big position that connects the entire fretboard. I think that guitarist was talking about modes and stuff. The major scale has 7 notes so there are 7 positions. One of these positions (though it would take another topic to explain why this makes sense) is the minor scale, and the other 5 positions will give you the other five modes. So if you know the major scale through and through for the entire fret board you can easily play the minor scale and the other 5 modes too, the diatonic scales (on a side note if you knew the minor scale through and through the same would apply). The minor pent is the minor scale with 2 notes taken out and the blues scale is the minor pent scale with a note added in, so it wouldnt take a long time to go from playing the minor scale into playing the blues scale (but i would recommend the reverse). But to say that is all you need to know is misleading. If a backing track is currently playing a C chord, then the notes C, E and G will be different then say if a Dm chord is playing becauser C, E and G are the notes that make up the C chords, the chord tones. That is important, so you would be able to play a solo w/o hitting a bad not if you knew the major scale through and through but you would play much better if you were aware of what chord was being played and how the notes that you are playing will be different. And to know the major scale though and through takes some time so study chord tones along the way

If you learn how to play songs, then you learn songs. If you learn how to improvise, then you learn music.