Index Of Jpg/up Is The Index Finger On Your Picking Hand Supposed To Touch The Strings Of The Guitar?

Is the index finger on your picking hand supposed to touch the strings of the guitar? - index of jpg/up

When I play guitar, made the first choice between the thumb and forefinger. I will be selecting some of the trucks leaving the index finger bent inwards to give something, but my index finger starts to unravel as the game and starts playing the strings. So, my fingers always touching the ropes before you turn. If so, how should it be? This is a very important thing when you play around with power chords and not too anxious to get his own, but it sucks when you play a single note.